Way 2 Freshers

1) 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’. (See the Bookstore section’s ‘Software QA’ category for a list of useful books on Software Quality Assurance.)

2) 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’. (See the Bookstore section’s ‘Software Testing’ category for a list of useful books on Software Testing.)

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.

3) What are some recent major computers system failures caused by software bugs?

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.
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.
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.

4) 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.”

5) Why does software have bugs?

miscommunication or no communication - as to specifics of what an application should or shouldn’t do (the application’s requirements).
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. programming errors - programmers, like anyone else, can make mistakes. 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 - see ‘What can be done if requirements are changing continuously?’ in Part 2 of the FAQ. 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.

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’).
software development tools - visual tools, class libraries, compilers, scripting tools, etc. often introduce their own bugs or are poorly documented, resulting in added bugs.

6) How can new Software QA processes be introduced in an existing organization?

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.
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. 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. 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.

7) 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.

8) What is a ‘walkthrough’?
A ‘walkthrough’ is an informal meeting for evaluation or informational purposes. Little or no preparation is usually required.

9) What’s an ‘inspection’?
An inspection is more formalized than a ‘walkthrough’, typically with 3-8 people including a moderator, reader (the author of whatever is being reviewed), 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.

10) 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; testers should do this type of testing. 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.

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