Friday, July 23, 2010


               1. What is black box/white box testing?
Black-box and white-box are test design methods.  Black-box test design treats the system as a “black-box”, so it doesn’t explicitly use knowledge of the internal structure.  Black-box test design is usually described as focusing on testing functional requirements.  Synonyms for black-box include:  behavioral, functional, opaque-box, and closed-box.  White-box test design allows one to peek inside the “box”, and it focuses specifically on using internal knowledge of the software to guide the selection of test data.  Synonyms for white-box include: structural, glass-box and clear-box.
While black-box and white-box are terms that are still in popular use, many people prefer the terms "behavioral" and "structural".  Behavioral test design is slightly different from black-box test design because the use of internal knowledge isn't strictly forbidden, but it's still discouraged.  In practice, it hasn't proven useful to use a single test design method.  One has to use a mixture of different methods so that they aren't hindered by the limitations of a particular one.  Some call this "gray-box" or "translucent-box" test design, but others wish we'd stop talking about boxes altogether.
It is important to understand that these methods are used during the test design phase, and their influence is hard to see in the tests once they're implemented.  Note that any level of testing (unit testing, system testing, etc.) can use any test design methods.  Unit testing is usually associated with structural test design, but this is because testers usually don't have well-defined requirements at the unit level to validate.
2. What are unit, component and integration testing?
Note that the definitions of unit, component, integration, and     integration testing are recursive:
Unit.  The smallest compilable component.  A unit typically is the     work of one programmer (At least in principle).  As defined, it does     not include any called sub-components (for procedural languages) or     communicating components in general.
Unit Testing:  in unit testing called components (or communicating     components) are replaced with stubs, simulators, or trusted components.  Calling components are replaced with drivers or trusted super-components. The unit is tested in isolation.
component: a unit is a component. The integration of one or more     components is a component.
Note:  The reason for "one or more" as contrasted to "Two or more" is to allow for components that call themselves recursively.
component testing: the same as unit testing except that all stubs and simulators are replaced with the real thing.
Two components (actually one or more) are said to be integrated when:
            a. They have been compiled, linked, and loaded together.
  b.They have successfully passed the integration tests at the                 interface between them.
Thus, components A and B are integrated to create a new, larger, component (A,B).  Note that this does not conflict with the idea of incremental integration—it just means that A is a big component and B, the component added, is a small one.
Integration testing: carrying out integration tests.
Integration tests (After Leung and White) for procedural languages. This is easily  generalized for OO languages by using the equivalent constructs for message passing.  In the following, the word "call"  is to be understood in the most general sense of a data flow and is not restricted to just formal subroutine calls and returns – for example, passage of data through global data structures and/or the
use of pointers.
    Let A and B be two components in which A calls B.
    Let Ta be the component level tests of A
    Let Tb be the component level tests of B
    Tab    The tests in A's suite that cause A to call B.
    Tbsa  The tests in B's suite for which it is possible to sensitize A -- the inputs    
     are to A, not B.
    Tbsa + Tab == the integration test suite (+ = union).
Note: Sensitize is a technical term.  It means inputs that will cause a routine to go down a specified path.  The inputs are to A.  Not every input to A will cause A to traverse a path in which B is called.  Tbsa is the set of tests which do cause A to follow a path in which B is called.  The outcome of the test of B may or may not be affected.
There have been variations on these definitions, but the key point is that it is pretty darn formal and there's a goodly hunk of testing theory, especially as concerns integration testing, OO testing, and regression testing, based on them.
As to the difference between integration testing and system testing. System testing specifically goes after behaviors and bugs that are properties of the entire system as distinct from properties attributable to components (unless, of course, the component in question is the entire system).  Examples of system testing issues:
    resource loss bugs, throughput bugs, performance, security, recovery,
    transaction synchronization bugs (often misnamed "timing bugs").
3. What's the difference between load and stress testing ?
One of the most common, but unfortunate misuse of terminology is treating “load testing” and “stress testing” as synonymous.   The consequence of this ignorant semantic abuse is usually that the system is neither properly “load tested” nor subjected to a meaningful  stress test.
Stress testing is subjecting a system to an unreasonable load while denying it the resources (e.g., RAM, disc, mips, interrupts, etc.) needed to process that load.  The idea is to stress a system to the breaking point in order to find bugs that will make that break  potentially harmful.  The system is not expected to process the overload without adequate resources, but to behave (e.g., fail) in a decent manner (e.g., not corrupting or losing data).  Bugs and failure modes discovered under stress testing may or  may not be repaired depending on the application, the failure mode, consequences, etc. The load (incoming transaction stream) in stress testing is often deliberately distorted so as to force the system into resource depletion.
Load testing is subjecting a system to a statistically representative (usually) load.  The two main reasons for using such loads is in support of software reliability testing and in performance testing.  The term "load testing" by itself is too vague and imprecise to warrant use. For example, do you mean representative load," "overload," "high load," etc.  In performance testing, load is
varied from a minimum (zero) to the maximum level the system can sustain without running out of resources or having, transactions >suffer (application-specific) excessive delay.
A third use of the term is as a test whose objective is to determine the maximum sustainable load the system can handle. In this usage, "load testing" is merely testing at the highest transaction arrival rate in performance testing.
4. What's the difference between QA and testing?
QA is more a preventive thing, ensuring quality in the company and therefore the product rather than just testing the product for software bugs?
       TESTING means "quality control"
       QUALITY CONTROL measures the quality of a product
       QUALITY ASSURANCE measures the quality of processes used  to create a 
       quality product.
5. What is the best tester to developer ratio?
Reported tester:developer ratios range from 10:1 to 1:10.
There's no simple answer. It depends on so many things, Amount of reused code, number and type of interfaces, platform, quality goals, etc.
It also can depend on the development model.  The more specs, the less  testers.  The roles can play a big part also.  Does QA own beta?  Do you include process auditors or planning activities?
These figures can all vary very widely depending on how you define "tester" and "developer".  In some organizations, a "tester" is anyone who happens to be testing software at the time -- such as their own.  In other organizations, a "tester" is only a member of an independent test group.
It is far, far, better to ask about the test labor content than it is to ask about the tester/developer ratio.  The test labor content, across most applications is generally accepted as 50%, when people do honest accounting.  For life-critical software, this can go up to 80%.
6. What is Software Quality Assurance?
Software QA involves the entire software development PROCESS - monitoring and improving the process, making sure that any agreed-upon standards and procedures are followed, and ensuring that problems are found and dealt with. It is oriented to 'prevention'. 

7. What is Software Testing?

Testing involves operation of a system or application under controlled conditions and evaluating the results (eg, 'if the user is in interface A of the application while using hardware B, and does C, then D should happen'). The controlled conditions should include both normal and abnormal conditions. Testing should intentionally attempt to make things go wrong to determine if things happen when they shouldn't or things don't happen when they should. It is oriented to 'detection'.

Organizations vary considerably in how they assign responsibility for QA and testing. Sometimes they're the combined responsibility of one group or individual. Also common are project teams that include a mix of testers and developers who work closely together, with overall QA processes monitored by project managers. It will depend on what best fits an organization's size and business structure.
8. What are some recent major computer system failures caused by Software bugs?
Ø  In March of 2002 it was reported that software bugs in Britain's national tax system resulted in more than 100,000 erroneous tax overcharges. The problem was partly attibuted to the difficulty of testing the integration of multiple systems.
Ø  A newspaper columnist reported in July 2001 that a serious flaw was found in off-the-shelf software that had long been used in systems for tracking certain U.S. nuclear materials. The same software had been recently donated to another country to be used in tracking their own nuclear materials, and it was not until scientists in that country discovered the problem, and shared the information, that U.S. officials became aware of the problems.
Ø  According to newspaper stories in mid-2001, a major systems development contractor was fired and sued over problems with a large retirement plan management system. According to the reports, the client claimed that system deliveries were late, the software had excessive defects, and it caused other systems to crash.
Ø  In January of 2001 newspapers reported that a major European railroad was hit by the aftereffects of the Y2K bug. The company found that many of their newer trains would not run due to their inability to recognize the date '31/12/2000'; the trains were started by altering the control system's date settings.
Ø  News reports in September of 2000 told of a software vendor settling a lawsuit with a large mortgage lender; the vendor had reportedly delivered an online mortgage processing system that did not meet specifications, was delivered late, and didn't work.
Ø  In early 2000, major problems were reported with a new computer system in a large suburban U.S. public school district with 100,000+ students; problems included 10,000 erroneous report cards and students left stranded by failed class registration systems; the district's CIO was fired. The school district decided to reinstate it's original 25-year old system for at least a year until the bugs were worked out of the new system by the software vendors.
Ø  In October of 1999 the $125 million NASA Mars Climate Orbiter spacecraft was believed to be lost in space due to a simple data conversion error. It was determined that spacecraft software used certain data in English units that should have been in metric units. Among other tasks, the orbiter was to serve as a communications relay for the Mars Polar Lander mission, which failed for unknown reasons in December 1999. Several investigating panels were convened to determine the process failures that allowed the error to go undetected.
Ø  Bugs in software supporting a large commercial high-speed data network affected 70,000 business customers over a period of 8 days in August of 1999. Among those affected was the electronic trading system of the largest U.S. futures exchange, which was shut down for most of a week as a result of the outages.
Ø  In April of 1999 a software bug caused the failure of a $1.2 billion military satellite launch, the costliest unmanned accident in the history of Cape Canaveral launches. The failure was the latest in a string of launch failures, triggering a complete military and industry review of U.S. space launch programs, including software integration and testing processes. Congressional oversight hearings were requested.
Ø  A small town in Illinois received an unusually large monthly electric bill of $7 million in March of 1999. This was about 700 times larger than its normal bill. It turned out to be due to bugs in new software that had been purchased by the local power company to deal with Y2K software issues.
Ø  In early 1999 a major computer game company recalled all copies of a popular new product due to software problems. The company made a public apology for releasing a product before it was ready.
Ø  The computer system of a major online U.S. stock trading service failed during trading hours several times over a period of days in February of 1999 according to nationwide news reports. The problem was reportedly due to bugs in a software upgrade intended to speed online trade confirmations.
Ø  In April of 1998 a major U.S. data communications network failed for 24 hours, crippling a large part of some U.S. credit card transaction authorization systems as well as other large U.S. bank, retail, and government data systems. The cause was eventually traced to a software bug.
Ø  January 1998 news reports told of software problems at a major U.S. telecommunications company that resulted in no charges for long distance calls for a month for 400,000 customers. The problem went undetected until customers called up with questions about their bills.
Ø  In November of 1997 the stock of a major health industry company dropped 60% due to reports of failures in computer billing systems, problems with a large database conversion, and inadequate software testing. It was reported that more than $100,000,000 in receivables had to be written off and that multi-million dollar fines were levied on the company by government agencies.
Ø  A retail store chain filed suit in August of 1997 against a transaction processing system vendor (not a credit card company) due to the software's inability to handle credit cards with year 2000 expiration dates.
Ø  In August of 1997 one of the leading consumer credit reporting companies reportedly shut down their new public web site after less than two days of operation due to software problems. The new site allowed web site visitors instant access, for a small fee, to their personal credit reports. However, a number of initial users ended up viewing each others' reports instead of their own, resulting in irate customers and nationwide publicity. The problem was attributed to "...unexpectedly high demand from consumers and faulty software that routed the files to the wrong computers."
Ø  In November of 1996, newspapers reported that software bugs caused the 411 telephone information system of one of the U.S. RBOC's to fail for most of a day. Most of the 2000 operators had to search through phone books instead of using their 13,000,000-listing database. The bugs were introduced by new software modifications and the problem software had been installed on both the production and backup systems. A spokesman for the software vendor reportedly stated that 'It had nothing to do with the integrity of the software. It was human error.'
Ø  On June 4 1996 the first flight of the European Space Agency's new Ariane 5 rocket failed shortly after launching, resulting in an estimated uninsured loss of a half billion dollars. It was reportedly due to the lack of exception handling of a floating-point error in a conversion from a 64-bit integer to a 16-bit signed integer.
Ø  Software bugs caused the bank accounts of 823 customers of a major U.S. bank to be credited with $924,844,208.32 each in May of 1996, according to newspaper reports. The American Bankers Association claimed it was the largest such error in banking history. A bank spokesman said the programming errors were corrected and all funds were recovered.
Ø  Software bugs in a Soviet early-warning monitoring system nearly brought on nuclear war in 1983, according to news reports in early 1999. The software was supposed to filter out false missile detections caused by Soviet satellites picking up sunlight reflections off cloud-tops, but failed to do so. Disaster was averted when a Soviet commander, based on a what he said was a '...funny feeling in my gut', decided the apparent missile attack was a false alarm. The filtering software code was rewritten.
9. Why is it often hard for management to get serious about quality assurance?
Solving problems is a high-visibility process; preventing problems is low-visibility. This is illustrated by an old parable:
In ancient China there was a family of healers, one of whom was known throughout the land and employed as a physician to a great lord. The physician was asked which of his family was the most skillful healer. He replied, 

"I tend to the sick and dying with drastic and dramatic treatments, and on occasion someone is cured and my name gets out among the lords."

"My elder brother cures sickness when it just begins to take root, and his skills are known among the local peasants and neighbors." 

"My eldest brother is able to sense the spirit of sickness and eradicate it before it takes form. His name is unknown outside our home."
10. Why does Software have bugs?
Ø  miscommunication or no communication - as to specifics of what an application should or shouldn't do (the application's requirements).
Ø  software complexity - the complexity of current software applications can be difficult to comprehend for anyone without experience in modern-day software development. Windows-type interfaces, client-server and distributed applications, data communications, enormous relational databases, and sheer size of applications have all contributed to the exponential growth in software/system complexity. And the use of object-oriented techniques can complicate instead of simplify a project unless it is well-engineered.
Ø  programming errors - programmers, like anyone else, can make mistakes.
Ø  changing requirements - the customer may not understand the effects of changes, or may understand and request them anyway - redesign, rescheduling of engineers, effects on other projects, work already completed that may have to be redone or thrown out, hardware requirements that may be affected, etc. If there are many minor changes or any major changes, known and unknown dependencies among parts of the project are likely to interact and cause problems, and the complexity of keeping track of changes may result in errors. Enthusiasm of engineering staff may be affected. In some fast-changing business environments, continuously modified requirements may be a fact of life. In this case, management must understand the resulting risks, and QA and test engineers must adapt and plan for continuous extensive testing to keep the inevitable bugs from running out of control.
Ø  time pressures - scheduling of software projects is difficult at best, often requiring a lot of guesswork. When deadlines loom and the crunch comes, mistakes will be made.

egos - people prefer to say things like:

  'no problem'
  'piece of cake'
  'I can whip that out in a few hours'
  'it should be easy to update that old code'

 instead of:

  'that adds a lot of complexity and we could end up
     making a lot of mistakes'
  'we have no idea if we can do that; we'll wing it'
  'I can't estimate how long it will take, until I
     take a close look at it'
  'we can't figure out what that old spaghetti code
     did in the first place'

 If there are too many unrealistic 'no problem's', the  result is bugs.

Ø  poorly documented code - it's tough to maintain and modify code that is badly written or poorly documented; the result is bugs. In many organizations management provides no incentive for programmers to document their code or write clear, understandable code. In fact, it's usually the opposite: they get points mostly for quickly turning out code, and there's job security if nobody else can understand it ('if it was hard to write, it should be hard to read').
Ø  software development tools - visual tools, class libraries, compilers, scripting tools, etc. often introduce their own bugs or are poorly documented, resulting in added bugs.
11. How can new Software QA processes be introduced in an existing organization?
Ø  A lot depends on the size of the organization and the risks involved. For large organizations with high-risk (in terms of lives or property) projects, serious management buy-in is required and a formalized QA process is necessary.
Ø  Where the risk is lower, management and organizational buy-in and QA implementation may be a slower, step-at-a-time process. QA processes should be balanced with productivity so as to keep bureaucracy from getting out of hand.
Ø  For small groups or projects, a more ad-hoc process may be appropriate, depending on the type of customers and projects. A lot will depend on team leads or managers, feedback to developers, and ensuring adequate communications among customers, managers, developers, and testers.
Ø  In all cases the most value for effort will be in requirements management processes, with a goal of clear, complete, testable requirement specifications or expectations.
12. What is verification? validation?
Verification typically involves reviews and meetings to evaluate documents, plans, code, requirements, and specifications. This can be done with checklists, issues lists, walkthroughs, and inspection meetings. Validation typically involves actual testing and takes place after verifications are completed. The term 'IV & V' refers to Independent Verification and Validation.
13. What is a 'walkthrough'?
A 'walkthrough' is an informal meeting for evaluation or informational purposes. Little or no preparation is usually required.
14. What's an 'inspection'?
An inspection is more formalized than a 'walkthrough', typically with 3-8 people including a moderator, reader, and a recorder to take notes. The subject of the inspection is typically a document such as a requirements spec or a test plan, and the purpose is to find problems and see what's missing, not to fix anything. Attendees should prepare for this type of meeting by reading thru the document; most problems will be found during this preparation. The result of the inspection meeting should be a written report. Thorough preparation for inspections is difficult, painstaking work, but is one of the most cost effective methods of ensuring quality. Employees who are most skilled at inspections are like the 'eldest brother' in the parable in 'Why is it often hard for management to get serious about quality assurance?'. Their skill may have low visibility but they are extremely valuable to any software development organization, since bug prevention is far more cost-effective than bug detection.
15. What kinds of testing should be considered?
Black box testing - not based on any knowledge of internal design or code. Tests are based on requirements and functionality.

White box testing - based on knowledge of the internal logic of an application's code. Tests are based on coverage of code statements, branches, paths, conditions.

unit testing - the most 'micro' scale of testing; to test particular functions or code modules. Typically done by the programmer and not by testers, as it requires detailed knowledge of the internal program design and code. Not always easily done unless the application has a well-designed architecture with tight code; may require developing test driver modules or test harnesses.

incremental integration testing - continuous testing of an application as new functionality is added; requires that various aspects of an application's functionality be independent enough to work separately before all parts of the program are completed, or that test drivers be developed as needed; done by programmers or by testers.
integration testing - testing of combined parts of an application to determine if they function together correctly. The 'parts' can be code modules, individual applications, client and server applications on a network, etc. This type of testing is especially relevant to client/server and distributed systems.

functional testing - black-box type testing geared to functional requirements of an application; this type of testing should be done by testers. This doesn't mean that the programmers shouldn't check that their code works before releasing it (which of course applies to any stage of testing.)

system testing - black-box type testing that is based on overall requirements specifications; covers all combined parts of a system.

end-to-end testing - similar to system testing; the 'macro' end of the test scale; involves testing of a complete application environment in a situation that mimics real-world use, such as interacting with a database, using network communications, or interacting with other hardware, applications, or systems if appropriate.

sanity testing - typically an initial testing effort to determine if a new software version is performing well enough to accept it for a major testing effort. For example, if the new software is crashing systems every 5 minutes, bogging down systems to a crawl, or destroying databases, the software may not be in a 'sane' enough condition to warrant further testing in its current state.

regression testing - re-testing after fixes or modifications of the software or its environment. It can be difficult to determine how much re-testing is needed, especially near the end of the development cycle. Automated testing tools can be especially useful for this type of testing.

acceptance testing - final testing based on specifications of the end-user or customer, or based on use by end-users/customers over some limited period of time.

load testing - testing an application under heavy loads, such as testing of a web site under a range of loads to determine at what point the system's response time degrades or fails.

stress testing - term often used interchangeably with 'load' and 'performance' testing. Also used to describe such tests as system functional testing while under unusually heavy loads, heavy repetition of certain actions or inputs, input of large numerical values, large complex queries to a database system, etc.

performance testing - term often used interchangeably with 'stress' and 'load' testing. Ideally 'performance' testing (and any other 'type' of testing) is defined in requirements documentation or QA or Test Plans.

usability testing - testing for 'user-friendliness'. Clearly this is subjective, and will depend on the targeted end-user or customer. User interviews, surveys, video recording of user sessions, and other techniques can be used. Programmers and testers are usually not appropriate as usability testers.
install/uninstall testing - testing of full, partial, or upgrade install/uninstall processes.

recovery testing - testing how well a system recovers from crashes, hardware failures, or other catastrophic problems.

security testing - testing how well the system protects against unauthorized internal or external access, willful damage, etc; may require sophisticated testing techniques.

compatability testing - testing how well software performs in a particular hardware/software/operating system/network/etc. environment.

exploratory testing - often taken to mean a creative, informal software test that is not based on formal test plans or test cases; testers may be learning the software as they test it.

ad-hoc testing - similar to exploratory testing, but often taken to mean that the testers have significant understanding of the software before testing it.

user acceptance testing - determining if software is satisfactory to an end-user or customer.

comparison testing - comparing software weaknesses and strengths to competing products.

alpha testing - testing of an application when development is nearing completion; minor design changes may still be made as a result of such testing. Typically done by end-users or others, not by programmers or testers.

beta testing - testing when development and testing are essentially completed and final bugs and problems need to be found before final release. Typically done by end-users or others, not by programmers or testers.

mutation testing - a method for determining if a set of test data or test cases is useful, by deliberately introducing various code changes ('bugs') and retesting with the original test data/cases to determine if the 'bugs' are detected. Proper implementation requires large computational resources.
16. What are 5 common problems in the software development process?
poor requirements - if requirements are unclear, incomplete, too general, or not testable, there will be problems.

unrealistic schedule - if too much work is crammed in too little time, problems are inevitable.

inadequate testing - no one will know whether or not the program is any good until the customer complains or systems crash.

featuritis - requests to pile on new features after development is underway; extremely common.

miscommunication - if developers don't know what's needed or customer's have erroneous expectations, problems are guaranteed.
17. What are 5 common solutions to software development problems?
solid requirements - clear, complete, detailed, cohesive, attainable, testable requirements that are agreed to by all players. Use prototypes to help nail down requirements.

realistic schedules - allow adequate time for planning, design, testing, bug fixing, re-testing, changes, and documentation; personnel should be able to complete the project without burning out.

adequate testing - start testing early on, re-test after fixes or changes, plan for adequate time for testing and bug-fixing.

stick to initial requirements as much as possible - be prepared to defend against changes and additions once development has begun, and be prepared to explain consequences. If changes are necessary, they should be adequately reflected in related schedule changes. If possible, use rapid prototyping during the design phase so that customers can see what to expect. This will provide them a higher comfort level with their requirements decisions and minimize changes later on.

communication - require walkthroughs and inspections when appropriate; make extensive use of group communication tools - e-mail, groupware, networked bug-tracking tools and change management tools, intranet capabilities, etc.; insure that documentation is available and up-to-date - preferably electronic, not paper; promote teamwork and cooperation; use prototypes early on so that customers' expectations are clarified.
18. What is software 'quality'?                                                    
Quality software is reasonably bug-free, delivered on time and within budget, meets requirements and/or expectations, and is maintainable. However, quality is obviously a subjective term. It will depend on who the 'customer' is and their overall influence in the scheme of things. A wide-angle view of the 'customers' of a software development project might include end-users, customer acceptance testers, customer contract officers, customer management, the development organization's management/accountants/testers/salespeople, future software maintenance engineers, stockholders, magazine columnists, etc. Each type of 'customer' will have their own slant on 'quality' - the accounting department might define quality in terms of profits while an end-user might define quality as user-friendly and bug-free.
19. What is 'good code'?
'Good code' is code that works, is bug free, and is readable and maintainable. Some organizations have coding 'standards' that all developers are supposed to adhere to, but everyone has different ideas about what's best, or what is too many or too few rules. There are also various theories and metrics, such as McCabe Complexity metrics. It should be kept in mind that excessive use of standards and rules can stifle productivity and creativity. 'Peer reviews', 'buddy checks' code analysis tools, etc. can be used to check for problems and enforce 
For C and C++ coding, here are some typical ideas to consider in setting rules/standards; these may or may not apply to a particular situation:
Ø  minimize or eliminate use of global variables.
Ø  use descriptive function and method names - use both upper and lower case, avoid abbreviations, use as many characters as necessary to be adequately descriptive (use of more than 20 characters is not out of line); be consistent in naming conventions.
Ø  use descriptive variable names - use both upper and lower case, avoid abbreviations, use as many characters as necessary to be adequately descriptive (use of more than 20 characters is not out of line); be consistent in naming conventions.
Ø  function and method sizes should be minimized; less than 100 lines of code is good, less than 50 lines is preferable.
Ø  function descriptions should be clearly spelled out in comments preceding a function's code.
Ø  organize code for readability.
Ø  use whitespace generously - vertically and horizontally
Ø  each line of code should contain 70 characters max.
Ø  one code statement per line.
Ø  coding style should be consistent throught a program (eg, use of brackets, indentations, naming conventions, etc.)
Ø  in adding comments, err on the side of too many rather than too few comments; a common rule of thumb is that there should be at least as many lines of comments (including header blocks) as lines of code.
Ø  no matter how small, an application should include documentaion of the overall program function and flow (even a few paragraphs is better than nothing); or if possible a separate flow chart and detailed program documentation.
Ø  make extensive use of error handling procedures and status and error logging.
Ø  for C++, to minimize complexity and increase maintainability, avoid too many levels of inheritance in class heirarchies (relative to the size and complexity of the application). Minimize use of multiple inheritance, and minimize use of operator overloading (note that the Java programming language eliminates multiple inheritance and operator overloading.)
Ø  for C++, keep class methods small, less than 50 lines of code per method is preferable.
Ø  for C++, make liberal use of exception handlers
20. What is 'good design'?
'Design' could refer to many things, but often refers to 'functional design' or 'internal design'. Good internal design is indicated by software code whose overall structure is clear, understandable, easily modifiable, and maintainable; is robust with sufficient error-handling and status logging capability; and works correctly when implemented. Good functional design is indicated by an application whose functionality can be traced back to customer and end-user requirements. For programs that have a user interface, it's often a good idea to assume that the end user will have little computer knowledge and may not read a user manual or even the on-line help; some common rules-of-thumb include:

Ø  the program should act in a way that least surprises the user
Ø  it should always be evident to the user what can be done next and how to exit
Ø  the program shouldn't let the users do something stupid without warning them.
21. What is SEI? CMM? ISO? IEEE? ANSI? Will it help?
SEI: 'Software Engineering Institute' at Carnegie-Mellon University; initiated by the U.S. Defense Department to help improve software development processes.

CMM: 'Capability Maturity Model', developed by the SEI. It's a model of 5 levels of organizational 'maturity' that determine effectiveness in delivering quality software. It is geared to large organizations such as large U.S. Defense Department contractors. However, many of the QA processes involved are appropriate to any organization, and if reasonably applied can be helpful. Organizations can receive CMM ratings by undergoing assessments by qualified auditors.

Level 1 - characterized by chaos, periodic panics, and heroic efforts required by individuals to successfully complete projects.  Few if any processes in place;                  successes may not be repeatable.

Level 2 - software project tracking, requirements management, realistic planning, and configuration management processes are in place; successful practices can be repeated.

Level 3 - standard software development and maintenance processes are integrated throughout an organization; a Software Engineering Process Group is is in place to oversee software processes, and training programs are used to ensure understanding and compliance.

Level 4 - metrics are used to track productivity, processes, and products.  Project performance is predictable, and quality is consistently high.

Level 5 - the focus is on continuous process improvement. The impact of new processes and technologies can be predicted and effectively implemented when required.

Perspective on CMM ratings:  During 1997-2001, 1018 organizations were assessed.  Of those, 27% were rated at Level 1, 39% at 2, 23% at 3, 6% at 4, and  5% at 5.  (For ratings during the period 1992-96, 62% were at Level 1, 23% at 2, 13% at 3, 2% at 4, and 0.4% at 5.)  The median size of organizations was 100 software engineering/maintenance personnel; 32% of organizations were       U.S. federal contractors or agencies.  For those rated at Level 1, the most problematical key process area was in Software Quality Assurance.

ISO: 'International Organisation for Standardization' - The ISO 9001:2000 standard (which replaces the previous standard of 1994) concerns quality systems that are assessed by outside auditors, and it applies to many kinds of production and manufacturing organizations, not just software. It covers documentation, design, development, production, testing, installation, servicing, and other processes. The full set of standards consists of: (a)Q9001-2000 - Quality Management Systems: Requirements; (b)Q9000-2000 - Quality Management Systems: Fundamentals and Vocabulary; (c)Q9004-2000 - Quality Management Systems: Guidelines for Performance Improvements. To be ISO 9001 certified, a third-party auditor assesses an organization, and certification is typically good for about 3 years, after which a complete reassessment is required. Note that ISO certification does not necessarily indicate quality products - it indicates only that documented processes are followed.

IEEE: 'Institute of Electrical and Electronics Engineers' - among other things, creates standards such as 'IEEE Standard for Software Test Documentation' (IEEE/ANSI Standard 829), 'IEEE Standard of Software Unit Testing (IEEE/ANSI Standard 1008), 'IEEE Standard for Software Quality Assurance Plans' (IEEE/ANSI Standard 730), and others.

ANSI: 'American National Standards Institute', the primary industrial standards body in the U.S.; publishes some software-related standards in conjunction with the IEEE and ASQ (American Society for Quality).

Other software development process assessment methods besides CMM and ISO 9000 include SPICE, Trillium, TickIT. and Bootstrap.

The life cycle begins when an application is first conceived and ends when it is no longer in use. It includes aspects such as initial concept, requirements analysis, functional design, internal design, documentation planning, test planning, coding, document preparation, integration, testing, maintenance, updates, retesting, phase-out, and other aspects.

Possibly. For small projects, the time needed to learn and implement them may not be worth it. For larger projects, or on-going long-term projects they can be valuable.

A common type of automated tool is the 'record/playback' type. For example, a tester could click through all combinations of menu choices, dialog box choices, buttons, etc. in an application GUI and have them 'recorded' and the results logged by a tool. The 'recording' is typically in the form of text based on a scripting language that is interpretable by the testing tool. If new buttons are added, or some underlying code in the application is changed, etc. the application can then be retested by just 'playing back' the 'recorded' actions, and comparing the logging results to check effects of the changes. The problem with such tools is that if there are continual changes to the system being tested, the 'recordings' may have to be changed so much that it becomes very time-consuming to continuously update the scripts. Additionally, interpretation of results (screens, data, logs, etc.) can be a difficult task. Note that there are record/playback tools for text-based interfaces also, and for all types of platforms.

Other automated tools can include:

code analyzers - monitor code complexity, adherence to standards, etc.

coverage analyzers - these tools check which parts of the code have been exercised by a test, and may be oriented to code statement coverage,                       condition coverage, path coverage, etc.

memory analyzers - such as bounds-checkers and leak detectors.

load/performance test tools - for testing client/server and web applications under various load levels.

web test tools - to check that links are valid, HTML code usage is correct, client-side and server-side programs work, a web site's interactions are secure.

other tools - for test case management, documentation management, bug reporting, and configuration management.

A good test engineer has a 'test to break' attitude, an ability to take the point of view of the customer, a strong desire for quality, and an attention to detail. Tact and diplomacy are useful in maintaining a cooperative relationship with developers, and an ability to communicate with both technical (developers) and non-technical (customers, management) people is useful. Previous software development experience can be helpful as it provides a deeper understanding of the software development process, gives the tester an appreciation for the developers' point of view, and reduce the learning curve in automated test tool programming. Judgment skills are needed to assess high-risk areas of an application on which to focus testing efforts when time is limited.

The same qualities a good tester has are useful for a QA engineer. Additionally, they must be able to understand the entire software development process and how it can fit into the business approach and goals of the organization. Communication skills and the ability to understand various sides of issues are important. In organizations in the early stages of implementing QA processes, patience and diplomacy are especially needed. An ability to find problems as well as to see 'what's missing' is important for inspections and reviews.

A good QA, test, or QA/Test(combined) manager should:

Ø  be familiar with the software development process
Ø  be able to maintain enthusiasm of their team and promote a positive atmosphere, despite what is a somewhat 'negative' process (e.g., looking for or preventing problems)
Ø  be able to promote teamwork to increase productivity
Ø  be able to promote cooperation between software, test, and QA engineers
Ø  have the diplomatic skills needed to promote improvements in QA processes
Ø  have the ability to withstand pressures and say 'no' to other managers when quality is insufficient or QA processes are not being adhered to
Ø  have people judgement skills for hiring and keeping skilled personnel
Ø  be able to communicate with technical and non-technical people, engineers, managers, and customers.
Ø  be able to run meetings and keep them focused

Critical. (Note that documentation can be electronic, not necessarily paper.) QA practices should be documented such that they are repeatable. Specifications, designs, business rules, inspection reports, configurations, code changes, test plans, test cases, bug reports, user manuals, etc. should all be documented. There should ideally be a system for easily finding and obtaining documents and determining what documentation will have a particular piece of information. Change management for documentation should be used if possible.

One of the most reliable methods of insuring problems, or failure, in a complex software project is to have poorly documented requirements specifications. Requirements are the details describing an application's externally-perceived functionality and properties. Requirements should be clear, complete, reasonably detailed, cohesive, attainable, and testable. A non-testable requirement would be, for example, 'user-friendly' (too subjective). A testable requirement would be something like 'the user must enter their previously-assigned password to access the application'. Determining and organizing requirements details in a useful and efficient way can be a difficult effort; different methods are available depending on the particular project. Many books are available that describe various approaches to this task.

Care should be taken to involve ALL of a project's significant 'customers' in the requirements process. 'Customers' could be in-house personnel or out, and could include end-users, customer acceptance testers, customer contract officers, customer management, future software maintenance engineers, salespeople, etc. Anyone who could later derail the project if their expectations aren't met should be included if possible.

Organizations vary considerably in their handling of requirements specifications. Ideally, the requirements are spelled out in a document with statements such as 'The product shall.....'. 'Design' specifications should not be confused with 'requirements'; design specifications should be traceable back to the requirements.

In some organizations requirements may end up in high level project plans, functional specification documents, in design documents, or in other documents at various levels of detail. No matter what they are called, some type of documentation with detailed requirements will be needed by testers in order to properly plan and execute tests. Without such documentation, there will be no clear-cut way to determine if a software application is performing correctly.

The following are some of the steps to consider:

Ø  Obtain requirements, functional design, and internal design specifications and other necessary documents
Ø  Obtain budget and schedule requirements
Ø  Determine project-related personnel and their responsibilities, reporting requirements, required standards and processes (such as release processes, change processes, etc.)
Ø  Identify application's higher-risk aspects, set priorities, and determine scope and limitations of tests
Ø  Determine test approaches and methods - unit, integration, functional, system, load, usability tests, etc.
Ø  Determine test environment requirements (hardware, software, communications, etc.)
Ø  Determine test ware requirements (record/playback tools, coverage analyzers, test tracking, problem/bug tracking, etc.)
Ø  Determine test input data requirements
Ø  Identify tasks, those responsible for tasks, and labor requirements
Ø  Set schedule estimates, timelines, milestones
Ø  Determine input equivalence classes, boundary value analyses, error classes
Ø  Prepare test plan document and have needed reviews/approvals
Ø  Write test cases
Ø  Have needed reviews/inspections/approvals of test cases
Ø  Prepare test environment and testware, obtain needed user manuals/reference documents/configuration guides/installation guides, set up test tracking processes, set up logging and archiving processes, set up or obtain test input data
Ø  Obtain and install software releases
Ø  Perform tests
Ø  Evaluate and report results
Ø  Track problems/bugs and fixes
Ø  Retest as needed
Ø  Maintain and update test plans, test cases, test environment, and testware through life cycle

A software project test plan is a document that describes the objectives, scope, approach, and focus of a software testing effort. The process of preparing a test plan is a useful way to think through the efforts needed to validate the acceptability of a software product. The completed document will help people outside the test group understand the 'why' and 'how' of product validation. It should be thorough enough to be useful but not so thorough that no one outside the test group will read it. The following are some of the items that might be included in a test plan, depending on the particular project:

Ø  Title
Ø  Identification of software including version/release numbers
Ø  Revision history of document including authors, dates, approvals
Ø  Table of Contents
Ø  Purpose of document, intended audience
Ø  Objective of testing effort
Ø  Software product overview
Ø  Relevant related document list, such as requirements, design documents, other test plans, etc.
Ø  Relevant standards or legal requirements
Ø  Traceability requirements
Ø  Relevant naming conventions and identifier conventions
Ø  Overall software project organization and personnel/contact-info/responsibilities.
Ø  Test organization and personnel/contact-info/responsibilities
Ø  Assumptions and dependencies
Ø  Project risk analysis
Ø  Testing priorities and focus.
Ø  Scope and limitations of testing
Ø  Test outline - a decomposition of the test approach by test type, feature, functionality, process, system, module, etc. as applicable
Ø  Outline of data input equivalence classes, boundary value analysis, error classes
Ø  Test environment - hardware, operating systems, other required software, data configurations, interfaces to other systems
Ø  Test environment validity analysis - differences between the test and production systems and their impact on test validity.
Ø  Test environment setup and configuration issues
Ø  Software migration processes
Ø  Software CM processes
Ø  Test data setup requirements
Ø  Database setup requirements
Ø  Outline of system-logging/error-logging/other capabilities, and tools such as screen capture software, that will be used to help describe and report bugs
Ø  Discussion of any specialized software or hardware tools that will be used by testers to help track the cause or source of bugs
Ø  Test automation - justification and overview
Ø  Test tools to be used, including versions, patches, etc.
Ø  Test script/test code maintenance processes and version control
Ø  Problem tracking and resolution - tools and processes
Ø  Project test metrics to be used
Ø  Reporting requirements and testing deliverables
Ø  Software entrance and exit criteria
Ø  Initial sanity testing period and criteria
Ø  Test suspension and restart criteria
Ø  Personnel allocation
Ø  Personnel pre-training needs
Ø  Test site/location
Ø  Outside test organizations to be utilized and their purpose, responsibilities, deliverables, contact persons, and coordination issues
Ø  Relevant proprietary, classified, security, and licensing issues.
Ø  Open issues
Ø  Appendix - glossary, acronyms, etc.

Ø  A test case is a document that describes an input, action, or event and an expected response, to determine if a feature of an application is working correctly. A test case should contain particulars such as test case identifier, test case name, objective, test conditions/setup, input data requirements, steps, and expected results.

Ø  Note that the process of developing test cases can help find problems in the requirements or design of an application, since it requires completely thinking through the operation of the application. For this reason, it's useful to prepare test cases early in the development cycle if possible.

The bug needs to be communicated and assigned to developers that can fix it. After the problem is resolved, fixes should be re-tested, and determinations made regarding requirements for regression testing to check that fixes didn't create problems elsewhere. If a problem-tracking system is in place, it should encapsulate these processes. A variety of commercial problem-tracking/management software tools are available. The following are items to consider in the tracking process:

Ø  Complete information such that developers can understand the bug, get an idea of it's severity, and reproduce it if necessary.
Ø  Bug identifier (number, ID, etc.)
Ø  Current bug status (e.g., 'Released for Retest', 'New', etc.)
Ø  The application name or identifier and version
Ø  The function, module, feature, object, screen, etc. where the bug occurred
Ø  Environment specifics, system, platform, relevant hardware specifics
Ø  Test case name/number/identifier
Ø  One-line bug description
Ø  Full bug description
Ø  Description of steps needed to reproduce the bug if not covered by a test case or if the developer doesn't have easy access to the test case/test script/test tool
Ø  Names and/or descriptions of file/data/messages/etc. used in test
Ø  File excerpts/error messages/log file excerpts/screen shots/test tool logs that would be helpful in finding the cause of the problem
Ø  Severity estimate (a 5-level range such as 1-5 or 'critical'-to-'low' is common)
Ø  Was the bug reproducible?
Ø  Tester name
Ø  Test date
Ø  Bug reporting date
Ø  Name of developer/group/organization the problem is assigned to
Ø  Description of problem cause
Ø  Description of fix
Ø  Code section/file/module/class/method that was fixed
Ø  Date of fix
Ø  Application version that contains the fix
Ø  Tester responsible for retest
Ø  Retest date
Ø  Retest results
Ø  Regression testing requirements
Ø  Tester responsible for regression tests
Ø  Regression testing results

A reporting or tracking process should enable notification of appropriate personnel at various stages. For instance, testers need to know when retesting is needed, developers need to know when bugs are found and how to get the needed information, and reporting/summary capabilities are needed for managers.

Configuration management covers the processes used to control, coordinate, and track: code, requirements, documentation, problems, change requests, designs, tools/compilers/libraries/patches, changes made to them, and who makes the changes.

The best bet in this situation is for the testers to go through the process of reporting whatever bugs or blocking-type problems initially show up, with the focus being on critical bugs. Since this type of problem can severely affect schedules, and indicates deeper problems in the software development process (such as insufficient unit testing or insufficient integration testing, poor design, improper build or release procedures, etc.) managers should be notified, and provided with some documentation as evidence of the problem.

This can be difficult to determine. Many modern software applications are so complex, and run in such an interdependent environment, that complete testing can never be done. Common factors in deciding when to stop are:

Ø  Deadlines (release deadlines, testing deadlines, etc.)
Ø  Test cases completed with certain percentage passed
Ø  Test budget depleted
Ø  Coverage of code/functionality/requirements reaches a specified point
Ø  Bug rate falls below a certain level
Ø  Beta or alpha testing period ends

Use risk analysis to determine where testing should be focused.
Since it's rarely possible to test every possible aspect of an application, every possible combination of events, every dependency, or everything that could go wrong, risk analysis is appropriate to most software development projects. This requires judgment skills, common sense, and experience. (If warranted, formal methods are also available.) Considerations can include:

Ø  Which functionality is most important to the project's intended purpose?
Ø  Which functionality is most visible to the user?
Ø  Which functionality has the largest safety impact?
Ø  Which functionality has the largest financial impact on users?
Ø  Which aspects of the application are most important to the customer?
Ø  Which aspects of the application can be tested early in the development cycle?
Ø  Which parts of the code are most complex, and thus most subject to errors?
Ø  Which parts of the application were developed in rush or panic mode?
Ø  Which aspects of similar/related previous projects caused problems?
Ø  Which aspects of similar/related previous projects had large maintenance expenses?
Ø  Which parts of the requirements and design are unclear or poorly thought out?
Ø  What do the developers think are the highest-risk aspects of the application?
Ø  What kinds of problems would cause the worst publicity?
Ø  What kinds of problems would cause the most customer service complaints?
Ø  What kinds of tests could easily cover multiple functionalities?
Ø  Which tests will have the best high-risk-coverage to time-required ratio?

A common problem and a major headache.

Ø  Work with the project's stakeholders early on to understand how requirements might change so that alternate test plans and strategies can be worked out in advance, if possible.
Ø  It's helpful if the application's initial design allows for some adaptability so that later changes do not require redoing the application from scratch.
Ø  If the code is well-commented and well-documented this makes changes easier for the developers.
Ø  Use rapid prototyping whenever possible to help customers feel sure of their requirements and minimize changes.
Ø  The project's initial schedule should allow for some extra time commensurate with the possibility of changes.
Ø  Try to move new requirements to a 'Phase 2' version of an application, while using the original requirements for the 'Phase 1' version.
Ø  Negotiate to allow only easily-implemented new requirements into the project, while moving more difficult new requirements into future versions of the application.
Ø  Be sure that customers and management understand the scheduling impacts, inherent risks, and costs of significant requirements changes. Then let management or the customers (not the developers or testers) decide if the changes are warranted - after all, that's their job.
Ø  Balance the effort put into setting up automated testing with the expected effort required to re-do them to deal with changes.
Ø  Try to design some flexibility into automated test scripts.
Ø  Focus initial automated testing on application aspects that are most likely to remain unchanged.
Ø  Devote appropriate effort to risk analysis of changes to minimize regression testing needs.
Ø  Design some flexibility into test cases (this is not easily done; the best bet might be to minimize the detail in the test cases, or set up only higher-level generic-type test plans)
Ø  Focus less on detailed test plans and test cases and more on ad hoc testing (with an understanding of the added risk that this entails).

Consider the impact of project errors, not the size of the project. However, if extensive testing is still not justified, risk analysis is again needed and the same considerations as described previously in 'What if there isn't enough time for thorough testing?' apply. The tester might then do ad hoc testing, or write up a limited test plan based on the risk analysis.

It may take serious effort to determine if an application has significant unexpected or hidden functionality, and it would indicate deeper problems in the software development process. If the functionality isn't necessary to the purpose of the application, it should be removed, as it may have unknown impacts or dependencies that were not taken into account by the designer or the customer. If not removed, design information will be needed to determine added testing needs or regression testing needs. Management should be made aware of any significant added risks as a result of the unexpected functionality. If the functionality only effects areas such as minor improvements in the user interface, for example, it may not be a significant risk.

By implementing QA processes slowly over time, using consensus to reach agreement on processes, and adjusting and experimenting as an organization grows and matures, productivity will be improved instead of stifled. Problem prevention will lessen the need for problem detection, panics and burn-out will decrease, and there will be improved focus and less wasted effort. At the same time, attempts should be made to keep processes simple and efficient, minimize paperwork, promote computer-based processes and automated tracking and reporting, minimize time required in meetings, and promote training as part of the QA process. However, no one - especially talented technical types - likes rules or bureaucracy, and in the short run things may slow down a bit. A typical scenario would be that more days of planning and development will be needed, but less time will be required for late-night bug-fixing and calming of irate customers.

This is a common problem in the software industry, especially in new technology areas. There is no easy solution in this situation, other than:

Ø  Hire good people
Ø  Management should 'ruthlessly prioritize' quality issues and maintain focus on the customer
Ø  Everyone in the organization should be clear on what 'quality' means to the customer

Client/server applications can be quite complex due to the multiple dependencies among clients, data communications, hardware, and servers. Thus testing requirements can be extensive. When time is limited (as it usually is) the focus should be on integration and system testing. Additionally, load/stress/performance testing may be useful in determining client/server application limitations and capabilities. There are commercial tools to assist with such testing.

Web sites are essentially client/server applications - with web servers and 'browser' clients. Consideration should be given to the interactions between html pages, TCP/IP communications, Internet connections, firewalls, applications that run in web pages (such as applets, javascript, plug-in applications), and applications that run on the server side (such as cgi scripts, database interfaces, logging applications, dynamic page generators, asp, etc.). Additionally, there are a wide variety of servers and browsers, various versions of each, small but sometimes significant differences between them, variations in connection speeds, rapidly changing technologies, and multiple standards and protocols. The end result is that testing for web sites can become a major ongoing effort. Other considerations might include:
Ø  What are the expected loads on the server (e.g., number of hits per unit time?), and what kind of performance is required under such loads (such as web server response time, database query response times). What kinds of tools will be needed for performance testing (such as web load testing tools, other tools already in house that can be adapted, web robot downloading tools, etc.)?
Ø  Who is the target audience? What kind of browsers will they be using? What kind of connection speeds will they by using? Are they intra- organization (thus with likely high connection speeds and similar browsers) or Internet-wide (thus with a wide variety of connection speeds and browser types)?
Ø  What kind of performance is expected on the client side (e.g., how fast should pages appear, how fast should animations, applets, etc. load and run)?
Ø  Will down time for server and content maintenance/upgrades be allowed? how much?
Ø  What kinds of security (firewalls, encryptions, passwords, etc.) will be required and what is it expected to do? How can it be tested?
Ø  How reliable are the site's Internet connections required to be? And how does that affect backup system or redundant connection requirements and testing?
Ø  What processes will be required to manage updates to the web site's content, and what are the requirements for maintaining, tracking, and controlling page content, graphics, links, etc.?
Ø  Which HTML specification will be adhered to? How strictly? What variations will be allowed for targeted browsers?
Ø  Will there be any standards or requirements for page appearance and/or graphics throughout a site or parts of a site??
Ø  How will internal and external links be validated and updated? how often?
Ø  Can testing be done on the production system, or will a separate test system be required? How are browser caching, variations in browser option settings, dial-up connection variabilities, and real-world internet 'traffic congestion' problems to be accounted for in testing?
Ø  How extensive or customized are the server logging and reporting requirements; are they considered an integral part of the system and do they require testing?
Ø  How are cgi programs, applets, java scripts, ActiveX components, etc. to be maintained, tracked, controlled, and tested?
Ø  Pages should be 3-5 screens max unless content is tightly focused on a single topic. If larger, provide internal links within the page.
Ø  The page layouts and design elements should be consistent throughout a site, so that it's clear to the user that they're still within a site.
Ø  Pages should be as browser-independent as possible, or pages should be provided or generated based on the browser-type.
Ø  All pages should have links external to the page; there should be no dead-end pages.
Ø  The page owner, revision date, and a link to a contact person or organization should be included on each page.

Well-engineered object-oriented design can make it easier to trace from code to internal design to functional design to requirements. While there will be little affect on black box testing (where an understanding of the internal design of the application is unnecessary), white-box testing can be oriented to the application's objects. If the application was well-designed this can simplify test design.

Extreme Programming (XP) is a software development approach for small teams on risk-prone projects with unstable requirements. It was created by Kent Beck who described the approach in his book 'Extreme Programming Explained'. Testing ('extreme testing') is a core aspect of Extreme Programming. Programmers are expected to write unit and functional test code first - before the application is developed. Test code is under source control along with the rest of the code. Customers are expected to be an integral part of the project team and to help develop scenarios for acceptance/black box testing. Acceptance tests are preferably automated, and are modified and rerun for each of the frequent development iterations. QA and test personnel are also required to be an integral part of the project team. Detailed requirements documentation is not used, and frequent re-scheduling, re-estimating, and re-prioritizing is expected.

46.ISO, CMM and Six Sigma:

ISO: ISO stands for International Organization for Standardization. The main office is in Geneva, Switzerland. The numbers 9000,9001 etc. these are all the numbers for quality system standardization.

Main objective:  The main objective of ISO is

1.To export the products to the European market.
2.For competitive sake.
3.The products quality should be same anywhere.

ISO-9000: QA system for guiding (guidelines) for selection and use. This will provide some guidelines to the organization.

ISO-9001: Quality assurance system for design, development, production, installations and services.

ISO-9002: Except design, rest of iso-9000. That is QA for development, production, installation and services.

ISO-9003: QA system for Final inspection and testing.

ISO-9004: QA system for performance and testing.

ISI specifies the products quality where as ISO specifies the company’s quality.

The ISO certification will be given by KPMG/BVQI. BVQI stands for Beauro Veritas Quality International.

CMM stands for capability maturity model. This is useful for software only. This was founded by SEI (Software Engineering Institute), Pitsburg, and USA.

Main Objectives:

1.To make immature mode to mature mode.
2.To identify areas for improvement.
3.This is useful for s/w only.
4.To improve the weak process.

There are 5 levels in CMM. They are

1.CMM LEVEL 1: (Initial): The project team and project manager should fit up to the group or company.

2.CMM LEVEL 2:(Repeatable): The project management is well defined and the project management should have certain responsibilities.

3.CMM LEVEL 3:(Defined): Software process is defined and standardized.

4.CMM LEVEL 4:(Manageable): Quality and Quantity to be produced and established.

5.CMM LEVEL 5: (Research & Development): Defect Change management, process change Management and Technology management. These are 3 Kappa’s (Key process Areas). And CMM level 4 company satisfies such 15 KPA's where as CMM LEVEL 5 satisfies such 18 KPA's.

Six Sigma: This was founded by Motorala, USA.

Def: The inherit the variance between the process and product is called Six Sigma. And sigma stands for Standard Deviation. The confirmation to the customer specifications or satisfaction is 99.75. And it should become 100%.

47. Testing Life Cycle: The testing life cycle involves the following stages.

1.Test plan preparation.
2.Test procedures and test development.
3.Test execution.
5.Defect Tracking

Testing is there at every stage of the life cycle. Even at the planning stage testing is there. But there testing people will be rarely involved at that stage. The senior developers and Business people only will do the testing. They will check weather the requirements are correct or not and Are they testable.  Are they reasonable? R they reachable etc. these all will be tested.

The testing effort starts immediately after receiving the Requirements analysis and Functional definition. The functional definition bridges the engineering design documents and the requirements analysis. SRS is the best example for the functional definition.
Test plan: A test plan is a strategic document, which consists of the complete information of the software process. It describes what are the scope, approach, Resources and testing intended activities. It identifies the tasks to be tested, items, features to be tested and which has to be assign to whom and risk requirements etc.

While preparing the test cases there are some components for preparing the test plan. They are

    1.Lists: includes
 List of reports.
 List of input/output variables.
 List of program files.
 List of Hardware environments
 List of software environments.
 List of features.
 List of operating system environments.

    2.Tables: This includes

 Table of reports.
 Table of input/output variables.
 Table of output values.
 Decision table.

   3.Outlines: This includes:

            Function list

   4.Matrices: These includes

            Printer compatibility matrix. etc.

2.Test procedures and test development: Test cases and test procedures will be prepared.

Test Case: A test case is nothing but a verification point. And here the strategy is an input, action and output. What are the inputs we are giving and what are the outputs we are getting and what are the actual output values and what are the expected output values and we have to compare these two values. If there is any difference then we have to track the bug till they correct by the developer.

While preparing the test cases we have to consider so many things like Equivalence class, Ranges of values, Boundary conditions, Race conditions and regression tests. Equillance Class: Two values are said to be equivalence it they both are testing the same thing and if one fails the others will probably too fails.
A class of values are said to be aquiline if we believe that all are testing the same thing and if one fails the others will probably fails and if one succeeds the others also will probably too.
While preparing the equivalence classes we have to prepare both valid as well as invalid equivalence classes. For example, if we want to prepare the equivalence classes for the range of number between 1-99, The valid equivalence classes are all the number between 1 and 99, the values 1 and the value 99.The invalid equivalence class are all the numbers less than 1, and all the values greater than 99 and all non-numbers.

For boundary conditions, suppose we want to check the boundary conditions for 1-99 then the valid equivalence class are 1 and 99. And invalid equivalence class are all the values other than 1 and 99 and non-numbers.

Race Conditions: There are two events to be happened. Event A & Event B. Event 'A' has to be happened first and then the event 'B' has to be happened. If event 'B' has happened first and then even 'A' has happened then it is an error.

Regression testing as usual.

3. Test Execution: Executing the generating script at the earlier stage.

4. Result: After executing the script, the result of the application such as pass or fail of the application has have to be displayed in the Result.

5. Defect Tracking: In case if the application fails, then we have to track the bug till they correct by the developer.

    The defect life cycle is as follows:

1. Testing the application.
2. finding the bug.
3. Sending the bug report to the developers for fixing.
4. Again testing the application once after the bug was fixed.
5. If again the bug comes then have to give the bug report to the developers.
6. Giving the reports to the management.

6.Report generation: Finally giving the reports with graphics or tables to the higher management.

48. Difference between Manual Testing and Automated Testing:

Manual Testing Disadvantages:

  1. Time consuming
  2. Low reliability
  3. Human Resources
  4. Inconsistent

Automated Testing advantages:

  1. speed
  2. Repeatability
  3. Programming Capabilities
  4. Coverage
  5. Reliability
  6. Reusability
7.   Less Human Resources

49. Which Test Cases to Automate?

1. Tests that need to be run for every build of the application (sanity check, regression test)

2. Tests that use multiple data values for the same actions (data driven tests)

3. Tests that require detailed information from application internals (e.g., SQL, GUI attributes)

4. Stress/load testing

           More repetitive the execution, better candidate for automation.

50. Which Test Cases Not to Automate?

1. Usability testing
       "How easy is the application to use?"

2. One-time testing

3. "We need to test NOW!"

4. Ad hoc/random testing
     based on intuition and knowledge of application

5. Tests without predictable results

           Improvisation required? Poor candidate for automation.

51. Testing v/s Life Cycle

Test Activity
Acceptance Test plan
Design (HL)
System Test plan , Integration Test plan
Unit Test plan
Unit test/debug
Integration test/debug, system test/debug
Acceptance test/ debug

52. Testing and debugging

n  The two terms are often used together; some programmers use them interchangeably

n  Purpose of testing

Ø  Show that a program has bugs

n  Purpose of debugging

Ø  Find the error/ misconception that led to failure and implement program changes that correct the error


Debugging is the act of attempting to determine the cause of the symptoms of malfunctions detected by testing or by frenzied user complaints.(Beizer)

Testing and Debugging

Starts with known conditions, user predefined procedures, predictable outcomes
Unknown initial conditions, end cannot be predicted
Should be planned, designed, scheduled
Cannot be constrained
Is a demonstration of error/apparent correctness
Is a deductive process
Proves a programmers “failure”
Vindicates a programmer
Should strive to be predictable, dull, constrained, rigid, inhuman.
Demands intuitive leaps, conjectures, experimentation, freedom.
Much can be done without design knowledge
Impossible without design knowledge
Can be done by outsider
Must be done by insider
Theory of testing available
Only recently have theorists started looking at it
Much of test design and execution cab be automated
Automation still a dream

53. Testing Standards

IEEE 829

Standard for Software Test Documentation

n  Applicable to all domains of software
n  Specifies the set of documents to be prepared as part of testing activities in a software project
n  Defines the purpose, outline and broad contents of each test document
n  Tailoring/combining may be required
n  Software Test Documentation include
Ø  Test Plans(**)
Ø  Test Design Specifications
Ø  Test Case Specifications
Ø  Test procedure specifications(**)
Ø  Test item Transmittal Report
Ø  Test Log(**)
Ø  Test Incident Report
Ø  Test Summary Report(**)
IEEE 829 Test Plan
n  Purpose
Ø  To identify items and features to be tested, tasks to be performed, responsibilities and schedules
n  Outline
1.      Identifier
2.      Introduction
3.      Test Items
4.      Features to be tested
5.      Features not to be tested
6.      Approach
7.      Pass/fail criteria
8.      Suspension criteria/resumption criteria
9.      Test deliverables
10.  Testing Tasks
11.  Environmental need
12.  Responsibilities
13.  Staffing and training need
14.  Schedule
15.  Risks and contingencies
16.  Approvals
IEEE 829 Test Design Specification

n  Purpose
Ø  To refine the test approach
n  Outline
1.    Test Design Specification Identifier
2.    Features to be tested
3.    Approach refinements
4.    Test identification
5.    Feature pass/fail criteria
IEEE 829 Test Case Specification

n  Purpose
Ø  To define a test case
n  Out line
1.    Test case specification identifier
2.    Test items
3.    Input specifications
4.    output specifications
5.    Environmental needs
6.    Special procedural requirements
7.    Inter-case dependencies

IEEE 829 Test Procedure Specification

n  Purpose
Ø  To specify steps for executing a set of cases or, more generally , the steps used to analyze a software item in order to evaluate a set of features
n  Outline
1.    Identifier
2.    Purpose
3.    Special Requirements
4.    Procedural steps, including
            Setup, proceed, evaluate, shutdown
IEEE 829 Test Item Transmittal Report

n  Purpose
Ø  To identify test items being transmitted for testing
n  Outline
1.    Identifier
2.    Transmitted items
3.    location
4.    status
5.    approvals
IEEE 829 Test log
n  Purpose
Ø  To provide a chronological record of relevant details about the execution of tests
n  Outline
1.    identifier
2.    description
3.    Activity and event entries with attachments
IEEE 829 Test Incident Report
n  Purpose
Ø  To document any event that occurs during testing which requires investigation.
n  Outline
1.    Identifier
2.    Summary
3.    Incident description
4.    Impact
IEEE 829 Test Summary Report

n Purpose

            To summarize the results of the designated testing activities and to             provide evaluations based on these results.

n  Outline

1.    Identifier
2.    Summary
3.    variances
4.    comprehensive assessment
5.    summary of results
6.    summary of activities
54.ETVX Model
To facilitate process control and ensure correctness and completeness of each activity the ETVX model is used.

Entry Criteria

Checklist of conditions that must be satisfied before beginning the activity


            A set of tasks that needs to be carried out


A list of tasks to verify the quality of work items prod iced

Exit Criteria

A checklist of conditions that must be satisfied before each activity is completed

Ø  Each phase in the development process can itself be considered a high level activity with a specific “ETVX”
Ø  A task or a verification task within an activity can itself be structured as a sub activity with “ETVX”
Ø  Some activities are performed only it certain conditions known as “Decision criteria” are met
Ø  Most of the activities in the process operate on work items.

Example: Coding and Unit test:

Entry criteria:

            Project plan is available
            SRS and HLD are available
            LLD and UTS are available for programs be tested
Tasks /Activities:

            Built program code
            Conduct unit test
            Setup environment for system test


Review code
Review unit test result

Exit Criteria:

            Reviewed and unit tested programs are available
            Refined STP & STS are available
            Refined user documentation is available.

55. Entrance and Exit Criteria

The concept of establishing pre-requisites (entrance criteria) and post conditions (exit criteria) for an activity to be undertaken is extremely useful for managing any process, testing being no exception.

Entrance criteria are those factors that must be present, at a minimum, to be able to start an activity. In Integration Testing for example, before a module can be integrated into a program, it must be compiled cleanly and have successfully completed unit testing.

If the entrance criteria of the next phase have been met, the next phase may be started even though the current phase is still under way. This is how overlapping schedules are allowed.

Exit criteria are those factors that must be present to declare an activity completed. To proclaim System Testing completed, two criteria might be that all test cases have been executed with a defined level of success (if other than 100%) and that there must be no more than a mutually agreed upon number of outstanding problems left unresolved. Exit criteria must be specifically expressed using terms such as, “X will be accepted if Y and Z are completed.”

You may view the User Acceptance Test as the Exit criteria for the development project.

56. Is testing synonymous with QA? (What’s the difference between QA and testing)

QA comprises activities that focus on defect prevention and process. Example is root causes for defects.

Testing is not QA activity, it is a quality control activity. QC focuses on detection and correction of defects. Example is Inspections.

57. Integration vs System Testing

An Integration Test will thus allow “flaws” in the application between different objects, components and modules etc to be uncovered while the Application is still being developed and the developers are still conceivably working in the same portion of the application. If the problem were to discovered in a system at the end of the development life cycle it would probably require more resources to correct than during the cycle. This is especially important in today’s market where the drive is to be the first to market a product. System testing specifically goes after behaviors and bugs that are properties of the entire system as distinct from properties attributable to components (unless, of course, the component in question is entire system). Examples of system testing issues: resource loss bugs, throughput bugs, performance, security, recovery, transaction synchronization bugs (often misnamed “timing bugs”).

Post a Comment

Receive All Free Updates Via Facebook.