Identify the scope, functional requirements and boundaries of a particular program. Pseudocode, flow charts and structure diagram ... that allow for the development of good software.

The technical report, ISA-TR5.1.01-ISA-TR77.40.01-2012, Functional Diagram Usage, expands upon and illustrates usage of function block symbols and functions, and prepares examples in development ...

The purpose and functional requirements can be defined in terms of inputs, processes and outputs. Pseudocode, flow charts and structure diagram are techniques that are used to design software.