Functional decomposition relates to the various functional relationships as how the original complex business functions were developed. It mainly focuses on how the overall functionality is developed and its interaction between various components.
It is used to break down the high-level solution scope of a project into its component parts. Then create a model of what needs to be done to deliver all or part of the solution. It is an outstanding way to break things into manageable pieces and understand the relationships between those pieces.
Business Analysts use Functional decomposition technique during the requirements analysis phase of a project to break either an organizational unit or the solution scope into its component parts. Each outcome may have its own set of requirements.
While building Work Break Down Structure (WBS) also Project Managers use it for their project and decomposing the project scope into its pieces and parts.
“Large or complex functionalities are more easily understood when broken down into pieces using functional decomposition.”
When and How
- It comes into picture in project requirement analysis phase in order to produce functional decomposition diagrams as part of the functional requirements document.
- After formal discussions with business analysts and subject matter expertise Functional Decomposition will be done.
- Decompose the components with their functions from root and continue to decompose to lower levels until a sufficient level of detail is achieved.
- Perform an end-to-end observation of the business operation and check each function to confirm that it is correct.
FD diagram for Course Management System