Acceptance testing is a process in product development whereby a prototype or product is heavy-duty and subjected to realistic environments and conditions (typically by customers) to ensure it can withstand normal or expected use. The goal of acceptance testing is to verify that the product meets specified requirements and is generally fit for purpose
There are typically three types of acceptance tests
1. alpha testing - carried out by internal staff at the developers' site
2. beta testing - carried out by external users at their own locations
3. operational acceptance testing - carried out by the operators of the system once it has been installed
Acceptance tests are usually performed at the end of the development process, but they may also be conducted at intermediate stages (e.g. after major functionality has been completed) in order to validate progress and identify any issues early on.