Task: Specify Design Function Details
This task decomposes a top-level function or local device manager of the functional design architecture to be implemented in software and specifies it in more detail.
Disciplines: Core Tasks
Purpose

The purpose of this task is to specify the internals of a design function of the functional design architecture, which is identified for implementation in software.

Relationships
Main Description
The top-level structure that already exists in the FDA is further refined in this task. A design function is decomposed into subfunctions and its internal behaviour is detailed or even formalized. The detailing and formalization of the internal behaviour can for instance be done by providing an executable model of the function, for instance by state machines and Simulink models.
During the decomposition and detailing of the design function, new information may emerge that calls for a change in the interfaces of the design function. For that reason, it is allowed to modify also the interfaces of the function, although it is not of primary concern for this task. This requires, however, close collaboration with the FDA architect.
In the decomposition and modeling process, certain assumptions and constraints on the environment and on the hardware platform may be derived. This is also to be documented in a separate work product.
Steps
Specify design function
This step decomposes the design function into subfunctions. The specification involves structuring and decomposition of functions to meet needs on allocation, sourcing, re-use, criticality, performance, etc.
Modify interfaces if necessary
This step may modify the interfaces specified by the top-level design, if new needs or findings are discovered during the detailed design of the function. However, this requires close cooperation with the FDA architect.
Identify design constraints
Assumptions and constraints that have been derived during the detailing process are identified and documented in a separate work product.