Why do we need Acceptance testing?

User Acceptance Testing (UAT), also called beta testing, is one sure way to reduce or eliminate change requests, and drastically reduce project costs. UAT is an effective process with a high rate of return for those who take the time to implement and follow its discipline.

Testing accomplishes a variety of things, but most importantly it measures the quality of the application. Testing presupposes there are defects in the software waiting to be discovered and this view is rarely disproved or even disputed. Several factors contribute to the importance of making UAT testing a high priority of any software development effort; these include:
• Reducing the cost of developing the application. Minimal savings that might occur in the early stages of the development cycle by delaying testing efforts are almost certainly bound to increase development costs later.
• Ensuring that the application behaves exactly as expected. For the vast majority of programs, unpredictability is the least desirable consequence of using an application.
• Reducing the total cost of ownership. By providing software that looks and behaves as shown in your documentation, your customers require fewer hours of training and less support from product experts.
• The goal of acceptance testing is to establish confidence in the system.
Acceptance testing is most often focused on a validation type testing.

The types of acceptance testing are:
• The User Acceptance test: focuses mainly on the functionality thereby validating the fitness-for-use of the system by the business user. The user acceptance test is performed by the users and application managers.
• The Operational Acceptance test: also known as Production acceptance test validates whether the system meets the requirements for operation. In most of the organization the operational acceptance test is performed by the system administration before the system is released. The operational acceptance test may include testing of backup/restore, disaster recovery, maintenance tasks and periodic check of security vulnerabilities.