SOFTWARE TESTING
What is 'Software Testing'?
Software testing is the process used to help identifythe correctness, completeness, security and quality of developed Computer software.It 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 (quality assurance ) 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 quality assurance processes monitored by project managers. It will depend on what best fits an organization's size and business structure.
Does every software project need testers?
While all projects will benefit from testing, some projects may not require independent test staff to succeed.
Which projects may not need independent test staff?
The answer depends on the size and context of the project, the risks, the development methodology, the skill and experience of the developers, and other factors. For instance, if the project is a short-term, small, low risk project, with highly experienced programmers utilizing thorough unit testing or test-first development, then test engineers may not be required for the project to succeed. In some cases an IT organization may be too small or new to have atesting staff even if the situation calls for it. In these circumstances it maybe appropriate to instead use contractors or outsourcing, or adjust the project management and development approach (by switching to more senior developers ).Inexperienced managers sometimes gamble on the success of a project by skipping thorough testing or having programmers do post-development functional testing of their own work, a decidedly high risk game.
Why does software have bugs?
-Software complexity -The complexity of current software applicationscan be difficult to comprehend for anyone without experience in modern day software development. Multi-tiered applications, 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.
- Programming errors - programmers, like anyone else, can make mistakes.
-Changing requirements (whether documented or undocumented) - the end-use 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 coordinating 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 test engineers must adapt and plan for continuous extensive testing to keep the inevitable bugs from running out of control - see
'What can be done if requirements are changing continuously
-Time pressures - Scheduling of software projects is difficult at best, often requiring lot of guesswork. When deadlines loom and the tension arises mistakes will be made.
-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, maintainable 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').
-Software development tools - visual tools, class libraries, compilers, scripting tools, etc. often introduce their own bugs or are poorly documented, resulting in added bugs.
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'scode. 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 newfunctionality 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 or smoke 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 corrupting 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 quality assurance 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.
-Fail over testing - typically used interchangeably with 'recovery testing'
-Security testing - testing how well the system protects against unauthorized internal or external access, willful damage, etc; may require sophisticated testing techniques.
-Compatibility 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.
-Context-driven testing - testing driven by an understanding of the environment, culture, and intended use of software. For example, the testing approach for life-critical medical equipment software would be completely different than that for a low-cost computer game.
-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.
What are 5 common problems in the software development process?
Poor requirements - if requirements are unclear, incomplete, too general, and 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.
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. In 'agile'-type environments, continuous close coordination with customers/end-users is necessary.
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. 'Early' testing ideally includes unit testing by developers and built-in testing and diagnostic capabilities.
Stick to initial requirements as much as possible - be prepared to defend against excessive 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, work closely with customers/end-users to manage expectations. This will provide them a higher comfort level with their requirements decisions and minimize excessive changes later on.
Communication - require walkthroughs and inspections when appropriate; make extensive use of group communication tools - groupware, wiki's, bug-tracking tools and change management tools, intranet capabilities, etc.; insure that information/documentation is available and up-to-date - preferably electronic,not paper; promote teamwork and cooperation; use protoypes and/or continuous communication with end-users if possible to clarify expectations.
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.
Certification
Many certification programs exist to support the professional aspirations of software testers. These include the CSQE program offered by the American Society for Quality, the CSTE/CSQA program offered by QAI, Quality Assuarance Institute, and the ISTQB certifications offered by ISTQB,International Software Testing Qualification Board. No certification currently offered actually requires the applicant to demonstrate the ability to test software. No certification is based on a widely accepted body of knowledge. This has led some to declare that the testing field is not ready for certification.
Few Helpful links on this topic
http://www.stickyminds.com/
http://www.satisfice.com/
http://www.testing.com/
http://software.wikicities.com/wiki/Main_Page
http://dmoz.org/Computers/Programming/Software_Testing/
http://en.wikipedia.org/wiki/Software_testing"
http://www.testmanagement.com/
What is 'Software Testing'?
Software testing is the process used to help identifythe correctness, completeness, security and quality of developed Computer software.It 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 (quality assurance ) 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 quality assurance processes monitored by project managers. It will depend on what best fits an organization's size and business structure.
Does every software project need testers?
While all projects will benefit from testing, some projects may not require independent test staff to succeed.
Which projects may not need independent test staff?
The answer depends on the size and context of the project, the risks, the development methodology, the skill and experience of the developers, and other factors. For instance, if the project is a short-term, small, low risk project, with highly experienced programmers utilizing thorough unit testing or test-first development, then test engineers may not be required for the project to succeed. In some cases an IT organization may be too small or new to have atesting staff even if the situation calls for it. In these circumstances it maybe appropriate to instead use contractors or outsourcing, or adjust the project management and development approach (by switching to more senior developers ).Inexperienced managers sometimes gamble on the success of a project by skipping thorough testing or having programmers do post-development functional testing of their own work, a decidedly high risk game.
Why does software have bugs?
-Software complexity -The complexity of current software applicationscan be difficult to comprehend for anyone without experience in modern day software development. Multi-tiered applications, 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.
- Programming errors - programmers, like anyone else, can make mistakes.
-Changing requirements (whether documented or undocumented) - the end-use 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 coordinating 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 test engineers must adapt and plan for continuous extensive testing to keep the inevitable bugs from running out of control - see
'What can be done if requirements are changing continuously
-Time pressures - Scheduling of software projects is difficult at best, often requiring lot of guesswork. When deadlines loom and the tension arises mistakes will be made.
-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, maintainable 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').
-Software development tools - visual tools, class libraries, compilers, scripting tools, etc. often introduce their own bugs or are poorly documented, resulting in added bugs.
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'scode. 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 newfunctionality 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 or smoke 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 corrupting 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 quality assurance 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.
-Fail over testing - typically used interchangeably with 'recovery testing'
-Security testing - testing how well the system protects against unauthorized internal or external access, willful damage, etc; may require sophisticated testing techniques.
-Compatibility 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.
-Context-driven testing - testing driven by an understanding of the environment, culture, and intended use of software. For example, the testing approach for life-critical medical equipment software would be completely different than that for a low-cost computer game.
-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.
What are 5 common problems in the software development process?
Poor requirements - if requirements are unclear, incomplete, too general, and 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.
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. In 'agile'-type environments, continuous close coordination with customers/end-users is necessary.
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. 'Early' testing ideally includes unit testing by developers and built-in testing and diagnostic capabilities.
Stick to initial requirements as much as possible - be prepared to defend against excessive 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, work closely with customers/end-users to manage expectations. This will provide them a higher comfort level with their requirements decisions and minimize excessive changes later on.
Communication - require walkthroughs and inspections when appropriate; make extensive use of group communication tools - groupware, wiki's, bug-tracking tools and change management tools, intranet capabilities, etc.; insure that information/documentation is available and up-to-date - preferably electronic,not paper; promote teamwork and cooperation; use protoypes and/or continuous communication with end-users if possible to clarify expectations.
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.
Certification
Many certification programs exist to support the professional aspirations of software testers. These include the CSQE program offered by the American Society for Quality, the CSTE/CSQA program offered by QAI, Quality Assuarance Institute, and the ISTQB certifications offered by ISTQB,International Software Testing Qualification Board. No certification currently offered actually requires the applicant to demonstrate the ability to test software. No certification is based on a widely accepted body of knowledge. This has led some to declare that the testing field is not ready for certification.
Few Helpful links on this topic
http://www.stickyminds.com/
http://www.satisfice.com/
http://www.testing.com/
http://software.wikicities.com/wiki/Main_Page
http://dmoz.org/Computers/Programming/Software_Testing/
http://en.wikipedia.org/wiki/Software_testing"
http://www.testmanagement.com/
posted by ndev at
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