High – level Design gives the overall System Design in terms of Functional Architecture and Database design. This is very useful for the developers to understand the flow of the system. In this phase design team, review team (testers) and customers plays a major role. For this the entry criteria are the requirement document that is SRS. And the exit criteria will be HLD, projects standards, the functional design documents, and the database design document.
Low – Level Design (LLD)
During the detailed phase, the view of the application developed during the high level design is broken down into modules and programs. Logic design is done for every program and then documented as program specifications. For every program, a unit test plan is created.
The entry criteria for this will be the HLD document. And the exit criteria will the program specification and unit test plan (LLD).
