In engineering and its various sub disciplines, acceptance testing is performed by the customer on a system prior to the customer accepting delivery or accepting transfer of ownership of that system. For systems, it is performed exclusively through black-box testing. Acceptance testing is also performed on lots (mechanical parts) or batches (chemicals) of manufactured or produced items.

Access controls are the collection of mechanisms that specify what users can do on the system, such as what resources they can access and operations they can perform. They are the countermeasures for ensuring that only users with the proper need and authority can access the system, are allowed to execute programs, and can read, edit, add and delete the appropriate information on that system. It builds on the basic issue addressed in the information security management domain, with an emphasis on various administrative, physical and technical/logical controls. Controls for gaining physical access to an area or to information have been used for centuries. The sender would speak the first secret word and wait for the correct secret word in response. If the response was not part of the shared secret words, access would not be granted. Although some other access control techniques are also used for physical security access to the information system.