Operational acceptance testing
Operational acceptance testing (OAT) is used to conduct operational readiness (pre-release) of a product, service, or system as part of a quality management system. OAT is a common type of non-functional software testing, used mainly in software development and software maintenance projects. This type of testing focuses on the operational readiness of the system to be supported, and/or to become part of the production environment. Hence, it is also known as operational readiness testing (ORT) or operations readiness and assurance testing (OR&A). Functional testing within OAT is limited to those tests which are required to  verify the "non-functional" aspects of the system. According to the International Software Testing Qualifications Board (ISTQB), OAT may include checking the backup/restore facilities, IT disaster recovery procedures, maintenance tasks and periodic check of security vulnerabilities., and whitepapers on ISO 29119 and Operational Acceptance by Anthony Woods, and ISO 25000 and Operational Acceptance Testing by Dirk Dach et al., OAT generally includes: During OAT changes may be made to environmental parameters which the application uses to run smoothly. For example, with Microsoft Windows applications with a mixed or hybrid architecture, this may include: Windows services, configuration files, web services , XML files, COM+ components, web services, IIS, stored procedures in databases, etc. Typically OAT should occur after each main phase of the development life cycle: design, build, and functional testing. In sequential projects it is often viewed as a "final" verification before a system is released; where in agile and iterative projects, a more frequent execution of OAT occurs providing stakeholders with assurance of continued stability of the system and its operating environment. An approach used in OAT may follow these steps: For running the OAT test cases, the tester normally has exclusive access to the system or environment. This  means that a single tester would be executing the test cases at a single point of time. For OAT the exact Operational Readiness quality gates are defined: both entry and exit gates. The primary emphasis of OAT should be on the operational stability, portability and reliability of the system.