Development, Testing, Acceptance and Production (DTAP) is a phased approach to software testing and deployment. The four letters in DTAP denote the following common steps: 1. * The program or component is developed on a Development system. This development environment might have no testing capabilities. 2. * Once the software developer thinks it is ready, the product is copied to a Test environment, to verify it works as expected. This test environment is supposedly standardized and in close alignment with the target environment. 3. * If the test is successful, the product is copied to an Acceptance test environment. During the Acceptance test, the customer will test the product in this environment to verify whether it meets their expectations. 4. * If the customer accepts the prod