Software QA and Testing Tools Info
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What's the best approach to software test estimation?
For example, given two software projects of similar complexity and size, the appropriate test effort for one project might be very large if it was for life-critical medical equipment software, but might be much smaller for the other project if it was for a low-cost computer game. A test estimation approach that only considered size and complexity might be appropriate for one project but not for the other.
How can it be determined if a test environment is appropriate?
What's the best way to choose a test automation tool?
Will automated testing tools make testing easier?
- Possibly. For small projects, the time needed to learn and implement them may not be worth it unless personnel are already familiar with the tools. 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. Usually the recorded script is manually modified and enhanced. If new buttons are added, or some underlying code in the application is changed, etc. the application might 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.
What if an organization is growing so fast that fixed QA processes are impossible?
- Hire good people
- Management should 'ruthlessly prioritize' quality issues and maintain focus on the customer
- Everyone in the organization should be clear on what 'quality' means to the customer
What if the application has functionality that wasn't in the requirements?
This problem is a standard aspect of projects that include COTS (Commercial Off-The-Shelf) software or modified COTS software. The COTS part of the project will typically have a large amount of functionality that is not included in project requirements, or may be simply undetermined. Depending on the situation, it may be appropriate to perform in-depth analysis of the COTS software and work closely with the end user to determine which pre-existing COTS functionality is important and which functionality may interact with or be affected by the non-COTS aspects of the project. A significant regression testing effort may be needed (again, depending on the situation), and automated regression testing may be useful.
How can Software QA processes be implemented without reducing productivity?
Other possibilities include incremental self-managed team approaches such as 'Kaizen' methods of continuous process improvement, the Deming-Shewhart Plan-Do-Check-Act cycle, and others.
What can be done if requirements are changing continuously?
- 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.
- 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.
- If the code is well-commented and well-documented this makes changes easier for the developers.
- Use some type of rapid prototyping whenever possible to help customers feel sure of their requirements and minimize changes.
- The project's initial schedule should allow for some extra time commensurate with the possibility of changes.
- Try to move new requirements to a 'Phase 2' version of an application, while using the original requirements for the 'Phase 1' version.
- Negotiate to allow only easily-implemented new requirements into the project, while moving more difficult new requirements into future versions of the application.
- 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.
- Balance the effort put into setting up automated testing with the expected effort required to refactor them to deal with changes.
- Try to design some flexibility into automated test scripts.
- Focus initial automated testing on application aspects that are most likely to remain unchanged.
- Devote appropriate effort to risk analysis of changes to minimize regression testing needs.
- 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)
- 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).
Who should decide when software is ready to be released?
A typical approach is for a lead tester or QA or Test manager to be the release decision maker. This again involves significant assumptions - such as an assumption that the test manager understands the spectrum of considerations that are important in determining whether software quality is 'sufficient' for release, or the assumption that quality does not have to be balanced with timeliness and cost. In many organizations, 'sufficient quality' is not well defined, is extremely subjective, may have never been usefully discussed, or may vary from project to project or even from day to day.
Release criteria considerations can include deadlines, sales goals, business/market/competitive considerations, business segment quality norms, legal requirements, technical and programming considerations, end-user expectations, internal budgets, impacts on other organization projects or goals, and a variety of other factors. Knowledge of all these factors is often shared among a number of personnel in a large organization, such as the project manager, director, customer service manager, technical lead or manager, marketing manager, QA manager, etc. In smaller organizations or projects it may be appropriate for one person to be knowledgeable in all these areas, but that person is typically a project manager, not a test lead or QA manager.
For these reasons, it's generally not a good idea for a test lead, test manager, or QA manager to decide when software is ready to be released. Their responsibility should be to provide input to the appropriate person or group that makes a release decision. For small organizations and projects that person could be a product manager, a project manager, or similar manager. For larger organizations and projects, release decisions might be made by a committee of personnel with sufficient collective knowledge of the relevant considerations.
Who is responsible for risk management?
It is not unusual for the term 'risk management' to never come up at all in a software organization or project. If it does come up, it's often assumed to be the responsibility of QA or test personnel. Or there may be a 'risks' or 'issues' section of a project, QA, or test plan, and it's assumed that this means that risk management has taken place.
The issues here are similar to those for the FAQ3 question "Who should decide when software is ready to be released?" It's generally NOT a good idea for a test lead, test manager, or QA manager to be the 'buck stops here' person for risk management. Typically QA/Test personnel or managers are not managers of developers, analysts, designers and many other project personnel, and so it would be difficult for them to ensure that everyone on a project is handling their risk management responsibilities. Additionally, knowledge of all the considerations that go into risk management mitigation and tradeoff decisions is rarely the province of QA/Test personnel or managers. Based on these factors, the project manager is usually the most appropriate 'buck stops here' risk management person. QA/Test personnel can, however, provide input to the project manager. Such input could include analysis of quality-related risks, risk monitoring, process adherence reporting, defect reporting, and other information.
Why is it often hard for organizations to get serious about quality assurance?
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."
This is a problem in any business, but it's a particularly difficult problem in the software industry. Software quality problems are often not as readily apparent as they might be in the case of an industry with more physical products, such as auto manufacturing or home construction.
Additionally: Many organizations are able to determine who is skilled at fixing problems, and then reward such people. However, determining who has a talent for preventing problems in the first place, and figuring out how to incentivize such behavior, is a significant challenge.
What is Extreme Programming and what's it got to do with testing?
How is testing affected by object-oriented designs?
How can World Wide Web sites be tested?
- 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, load generation appliances, etc.)?
- Who is the target audience? What kind and version of browsers will they be using, and how extensively should testing be for these variations? 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)?
- What kind of performance is expected on the client side (e.g., how fast should pages appear, how fast should flash, applets, etc. load and run)?
- Will down time for server and content maintenance/upgrades be allowed? how much?
- What kinds of security (firewalls, encryption, passwords, functionality, etc.) will be required and what is it expected to do? How can it be tested?
- What internationilization/localization/language requirements are there, and how are they to be verified?
- How reliable are the site's Internet connections required to be? And how does that affect backup system or redundant connection requirements and testing?
- 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.?
- Which HTML and related specification will be adhered to? How strictly? What variations will be allowed for targeted browsers?
- Will there be any standards or requirements for page appearance and/or graphics throughout a site or parts of a site?
- Will there be any development practices/standards utilized for web page components and identifiers, which can significantly impact test automation.
- How will internal and external links be validated and updated? how often?
- 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, connection variabilities, and real-world internet 'traffic congestion' problems to be accounted for in testing?
- 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?
- How are flash, applets, javascripts, ActiveX components, etc. to be maintained, tracked, controlled, and tested?
How does a client/server environment affect testing?
What if the project isn't big enough to justify extensive testing?
What if there isn't enough time for thorough testing?
- Which functionality is most important to the project's intended purpose?
- Which functionality is most visible to the user?
- Which functionality has the largest safety impact?
- Which functionality has the largest financial impact on users?
- Which aspects of the application are most important to the customer?
- Which aspects of the application can be tested early in the development cycle?
- Which parts of the code are most complex, and thus most subject to errors?
- Which parts of the application were developed in rush or panic mode?
- Which aspects of similar/related previous projects caused problems?
- Which aspects of similar/related previous projects had large maintenance expenses?
- Which parts of the requirements and design are unclear or poorly thought out?
- What do the developers think are the highest-risk aspects of the application?
- What kinds of problems would cause the worst publicity?
- What kinds of problems would cause the most customer service complaints?
- What kinds of tests could easily cover multiple functionalities?
- Which tests will have the best high-risk-coverage to time-required ratio?
How can it be known when to stop testing?
- Deadlines (release deadlines, testing deadlines, etc.)
- Test cases completed with certain percentage passed
- Test budget depleted
- Coverage of code/functionality/requirements reaches a specified point
- Bug rate falls below a certain level
- Beta or alpha testing period ends
What if the software is so buggy it can't really be tested at all?
What is 'Configuration Management'?
What should be done after a bug is found?
- Complete information such that developers can understand the bug, get an idea of it's severity, and reproduce it if necessary.
- Bug identifier (number, ID, etc.)
- Current bug status (e.g., 'Released for Retest', 'New', etc.)
- The application name or identifier and version
- The function, module, feature, object, screen, etc. where the bug occurred
- Environment specifics, system, platform, relevant hardware specifics
- Test case name/number/identifier
- One-line bug description
- Full bug description
- 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
- Names and/or descriptions of file/data/messages/etc. used in test
- File excerpts/error messages/log file excerpts/screen shots/test tool logs that would be helpful in finding the cause of the problem
- Severity estimate (a 5-level range such as 1-5 or 'critical'-to-'low' is common)
- Was the bug reproducible?
- Tester name
- Test date
- Bug reporting date
- Name of developer/group/organization the problem is assigned to
- Description of problem cause
- Description of fix
- Code section/file/module/class/method that was fixed
- Date of fix
- Application version that contains the fix
- Tester responsible for retest
- Retest date
- Retest results
- Regression testing requirements
- Tester responsible for regression tests
- Regression testing results
What's a 'test case'?
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.
What's a 'test plan'?
- Title
- Identification of software including version/release numbers
- Revision history of document including authors, dates, approvals
- Table of Contents
- Purpose of document, intended audience
- Objective of testing effort
- Software product overview
- Relevant related document list, such as requirements, design documents, other test plans, etc.
- Relevant standards or legal requirements
- Traceability requirements
- Relevant naming conventions and identifier conventions
- Overall software project organization and personnel/contact-info/responsibilties
- Test organization and personnel/contact-info/responsibilities
- Assumptions and dependencies
- Project risk analysis
- Testing priorities and focus
- Scope and limitations of testing
- Test outline - a decomposition of the test approach by test type, feature, functionality, process, system, module, etc. as applicable
- Outline of data input equivalence classes, boundary value analysis, error classes
- Test environment - hardware, operating systems, other required software, data configurations, interfaces to other systems
- Test environment validity analysis - differences between the test and production systems and their impact on test validity.
- Test environment setup and configuration issues
- Software migration processes
- Software CM processes
- Test data setup requirements
- Database setup requirements
- 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
- Discussion of any specialized software or hardware tools that will be used by testers to help track the cause or source of bugs
- Test automation - justification and overview
- Test tools to be used, including versions, patches, etc.
- Test script/test code maintenance processes and version control
- Problem tracking and resolution - tools and processes
- Project test metrics to be used
- Reporting requirements and testing deliverables
- Software entrance and exit criteria
- Initial sanity testing period and criteria
- Test suspension and restart criteria
- Personnel allocation
- Personnel pre-training needs
- Test site/location
- Outside test organizations to be utilized and their purpose, responsibilties, deliverables, contact persons, and coordination issues
- Relevant proprietary, classified, security, and licensing issues.
- Open issues
- Appendix - glossary, acronyms, etc.
What steps are needed to develop and run software tests?
- Obtain requirements, functional design, and internal design specifications, user stories, and other available/necessary information
- Obtain budget and schedule requirements
- Determine project-related personnel and their responsibilities, reporting requirements, required standards and processes (such as release processes, change processes, etc.)
- Determine project context, relative to the existing quality culture of the product/organization/business, and how it might impact testing scope, aproaches, and methods.
- Identify application's higher-risk and mor important aspects, set priorities, and determine scope and limitations of tests.
- Determine test approaches and methods - unit, integration, functional, system, security, load, usability tests, etc.
- Determine test environment requirements (hardware, software, configuration, versions, communications, etc.)
- Determine testware requirements (automation tools, coverage analyzers, test tracking, problem/bug tracking, etc.)
- Determine test input data requirements
- Identify tasks, those responsible for tasks, and labor requirements
- Set schedule estimates, timelines, milestones
- Determine, where apprapriate, input equivalence classes, boundary value analyses, error classes
- Prepare test plan document(s) and have needed reviews/approvals
- Write test cases
- Have needed reviews/inspections/approvals of test cases
- 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
- Obtain and install software releases
- Perform tests
- Evaluate and report results
- Track problems/bugs and fixes
- Retest as needed
- Maintain and update test plans, test cases, test environment, and testware through life cycle
What's the big deal about 'requirements'?
Care should be taken to involve ALL of a project's significant 'customers' in the requirements process. 'Customers' could be in-house personnel or outside personnel, 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. Often 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 are ideally 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.
'Agile' approaches use methods requiring close interaction and cooperation between programmers and customers/end-users to iteratively develop requirements, user stories, etc. In the XP 'test first' approach developers create automated unit testing code before the application code, and these automated unit tests essentially embody the requirements.
What's the role of documentation in QA?
What makes a good QA or Test manager?
- be familiar with the software development process
- 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)
- be able to promote teamwork to increase productivity
- be able to promote cooperation between software, test, and QA engineers
- have the diplomatic skills needed to promote improvements in QA processes
- have the ability to withstand pressures and say 'no' to other managers when quality is insufficient or QA processes are not being adhered to
- have people judgement skills for hiring and keeping skilled personnel
- be able to communicate with technical and non-technical people, engineers, managers, and customers.
- be able to run meetings and keep them focused
What makes a good Software QA engineer?
What makes a good Software Test engineer?
What is the 'software life cycle'?
What is SEI? CMM? CMMI? 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', now called the CMMI ('Capability Maturity Model Integration'), developed by the SEI. It's a model of 5 levels of process '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 CMMI ratings by undergoing assessments by qualified auditors
- ISO = 'International Organisation for Standardization' - The ISO 9001:2008 standard (which provides some clarifications of the previous standard 9001:2000) 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)Q9001-2008 - 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. Also see http://www.iso.org/ for the latest information. In the U.S. the standards can be purchased via the ASQ web site at http://www.asq.org/quality-press/ISO 9126 is a standard for the evaluation of software quality and defines six high level quality characteristics that can be used in software evaluation. It includes functionality, reliability, usability, efficiency, maintainability, and portability.
- 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/IT management process assessment methods besides CMMI and ISO 9000 include SPICE, Trillium, TickIT, Bootstrap, ITIL, MOF, and CobiT.
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. (See further discussion of functional and internal design in 'What's the big deal about requirements?' in FAQ #2.) 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 'good code'?
- 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 horizontally
- 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 software 'quality'?
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. In 'agile'-type environments, continuous close coordination with customers/end-users is necessary to ensure that changing/emerging requirements are understood.
- 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 could include static code analysis/testing, test-first development, unit testing by developers, built-in testing and diagnostic capabilities, automated post-build testing, etc.
- Stick to initial requirements where feasible - 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. In 'agile'-type environments, initial requirements may be expected to change significantly, requiring that true agile processes be in place and followed.
- 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.; ensure 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 are 5 common problems in the software development process?
- Poor requirements - if requirements are unclear, incomplete, too general, and not testable, there may 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 software is any good until customers complain or systems crash.
- Featuritis - requests to add on new features after development goals are agreed on.
- Miscommunication - if developers don't know what's needed or customer's have erroneous expectations, problems can be expected.
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 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 approaches 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.
- Failover 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.
- 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.
- 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 is verification? validation?
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'? 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 organizations 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.
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. - The most value for effort will often be in (a) requirements management processes, with a goal of clear, complete, testable requirement specifications embodied in requirements or design documentation, or in 'agile'-type environments extensive continuous coordination with end-users, (b) design inspections and code inspections, and (c) post-mortems/retrospectives.
- Other possibilities include incremental self-managed team approaches such as 'Kaizen' methods of continuous process improvement, the Deming-Shewhart Plan-Do-Check-Act cycle, and others. Also see 'How can QA processes be implemented without reducing productivity?'.
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. Multi-tier distributed systems, applications utilizing mutliple local and remote web services applications, data communications, enormous relational databases, security complexities, 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-user 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 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 the FAQ3. Also see information about 'agile' approaches such as XP, in the FAQ2.
- 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, 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.
Does every software project need testers?
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 a testing staff even if the situation calls for it. In these circumstances it may be appropriate to instead use contractors or outsourcing, or adjust the project management and development approach (by switching to more senior developers and agile test-first development, for example). 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 gamble.
For non-trivial-size projects or projects with non-trivial risks, a testing staff is usually necessary. As in any business, the use of personnel with specialized skills enhances an organization's ability to be successful in large, complex, or difficult tasks. It allows for both a) deeper and stronger skills and b) the contribution of differing perspectives. For example, programmers typically have the perspective of 'what are the technical issues in making this functionality work?'. A test engineer typically has the perspective of 'what might go wrong with this functionality, and how can we ensure it meets expectations?'. Technical people who can be highly effective in approaching tasks from both of those perspectives are rare, which is why, sooner or later, organizations bring in test specialists.
What is 'Software Testing'?
Reference books:
Lessons Learned in Software Testing, by C. Kaner, J. Bach, and B. Pettichord (2001)
Testing Computer Software, by C. Kaner, J. Falk, and H. Nguyen (1999)
Perfect Software and Other Illusions About Testing, by G. Weinberg (2008)
How to Break Web Software, by M. Andrews and J. Whittaker (2006)
Testing Applications on the Web, by H. Nguyen, R. Johnson, and M. Hackett (2003)
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.
What is 'Software Quality Assurance'?
Reference books:
Handbook of Software Quality Assurance, by G. Schulmeyer, et al (2007)
Quality Software Management: Vol. 4 Anticipating Change, by G. Weinberg (1997)
Practical Guide to Software Quality Management, by J. Horch (2003)
A Practical Guide to Information Systems Process Improvement, by A. Cassidy, et al (2000)
Managing the Software Process, by W. Humphrey (1989)
Customer Oriented Quality Assurance, by F. Ginac (1997)
The Capability Maturity Model: Guidelines for Improving the Software Process, by M. Paulk, et al (1995)
Software Inspection, by T. Gilb, et al (1993)
CMM in Practice, by P. Jalote (1999)
