Defining how each use case and process will translate into application behavior – usually an algorithmic definition of the process flow.

For example, in Software Development, a Process Flow Diagram (PFD), Data Flow Diagram (DFD) and an Entity-Relationship (E/R) Diagram will serve to elucidate the changes both at the processing (Application) layer and at the information persistence layer (Database). These are best documented in a Functional Requirements Document that expands on the requirements document. The following sections are advisable in a Functional Requirements Document (FRD)

• Requirements
• Application / Module Details
• Process Flows
• Data Flows
• Entity Relationships
• Use Cases

You may have to repeat the above sections for each Requirement / Application and Module in question.