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'.

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.

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 money) 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.

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.

What is a 'walkthrough'?

A 'walkthrough' is an informal meeting for evaluation or informational purposes. Little or no preparation is usually required.

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.

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 'performace' 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.

·        acceptance testing - determining if software is stisfactory to a 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.

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.

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 protoypes early on so that customers' expectations are clarified.

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.

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 standards.

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:

·        minimize or eliminate use of global variables.

·        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.

·        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.

·        function and method sizes should be minimized; less than 100 lines of code is good, less than 50 lines is preferable.

·        function descriptions should be clearly spelled out in comments preceding a function's code.

·        organize code for readability.

·        use whitespace generously - vertically and horizintally

·        each line of code should contain 70 characters max.

·        one code statement per line.

·        coding style should be consistent throught a program (eg, use of brackets, indentations, naming conventions, etc.)

·        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.

·        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.

·        make extensive use of error handling procedures and status and error logging.

·        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.)

·        for C++, keep class methods small, less than 50 lines of code per method is preferable.

·        for C++, make liberal use of exception handlers

 

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:

·        the program should act in a way that least surprises the user

·        it should always be evident to the user what can be done next and how to exit

·        the program shouldn't let the users do something stupid without warning them.

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 continouous process improvement. The impact of new processes and technologies can be predicted and effectively implemented when required.

·        ISO = 'International Organisation for Standards' - The ISO 9001, 9002, and 9003 standards concern quality systems that are assessed by outside auditors, and they apply to many kinds of production and manufacturing organizations, not just software. The most comprehensive is 9001, and this is the one most often used by software development organizations. It covers documentation, design, development, production, testing, installation, servicing, and other processes. ISO 9000-3 (not the same as 9003) is a guideline for applying ISO 9001 to software development organizations. The U.S. version of the ISO 9000 series standards is exactly the same as the international version, and is called the ANSI/ASQ Q9000 series. The U.S. version can be purchased directly from the ASQ (American Society for Quality) or the ANSI organizations. 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 9000 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.

What is the 'software life cycle'?

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.