• Assurance
• Qa
• Qa a
• Quality
• Quality assurance

Software testing

The quality of the application can and normally does vary widely from system to system but some of the common quality attributes include reliability, stability, portability, maintainability and usability. For a more complete listing of attributes it is suggested that the ISO standard ISO 9126 be consulted.

"An effective way to test code is to exercise it at its natural boundaries"

--Brian Kernighan

Table of contents

1 Introduction 1.1 Alpha testing 1.2 Beta testing 1.3 Gamma testing 2 See also 2.4 Software Testing Activities 3 External links

Introduction

In general, software engineers distinguish software faults and software failures. In case of a failure, the software does not do what the user expects. A fault is a programming error that does not actually manifest itself. A fault can also be described as an error in the correctness of the semantic of a computer program. A fault will become a failure if the exact computation conditions are met, one of them being that the faulty portion of computer software executes on the CPU . A fault can also turn into a failure when the software is ported to a different hardware platform or a different compiler, or when the software gets extended.

Software testing may be viewed as a sub-field of software quality assurance but typically exists independently (and there may be no SQA areas in some companies). In SQA, software process specialists and auditors take a broader view on software and its development. They examine and change the software engineering process itself to reduce the amount of faults that end up in the code or deliver faster.

Regardless of the methods used or level of formality involved the desired result of testing is a level of confidence in the software so that the developerss are confident that the software has an acceptable defect rate. What constitutes an acceptable defect rate depends on the nature of the software. An arcade video game designed to simulate flying an airplane would presumably have a much higher tolerance for defects than software used to control an actual airliner.

A problem with software testing is that the number of defects in a software product can be very large, and the number of configurations of the product larger still. Bugs that occur infrequently are difficult to find in testing. A rule of thumb is that a system that is expected to function without faults for a certain length of time must have already been tested for at least that length of time. This has severe consequences for projects to write long-lived reliable software.

One of the common misunderstandings of software testing is that it is performed by an independent group of testers after finishing the software product and before it is shipped to the customer. But this approach leads to the common effect that the test team is used as project buffer to compensate project delays. Additionally the earlier a defect is found the cheaper it is to fix it. Software testing starts at the same moment the project starts and it is a continuous process until the project finishes.

Alpha testing

Beta testing

Gamma testing

See also

• Code coverage
• Static code analysis
• Software engineering
• Formal verification
• Development stage
• Automated testing
• Black box testing
• Quality assurance
• Defect tracking
• Test-driven development

• System functional testing
• Unit testing
• Integration testing
• Regression testing
• Load testing
• Performance testing
• Stress testing
• Security testing
• Installation testing
• Usability testing
• Stability testing
• Authorization testing
• User acceptance testing
• Conformance testing

• Open Directory
• Citations from CiteSeer
• Software Testing and Quality Control - Outline
• Linux Kernel Scalable Test Platform
• OSDL Data Base Test Suite
• Agility an Issue and Requirements Tracking Software from AgileEdge
• Open source software testing tools
• The online community for software testing & quality assurance professionals
• QACity
• Stickyminds website for all things connected with software testing - associated with "Better Software" Magazine
• Methods & Tools: on-line magazine with many articles on software testing and quality