The following steps illustrate a top-down sequence of model development:
For each architecture module in the top level AFD, do the following steps:
- Create a new DFD containing those EDFD components enclosed within the superbubble that represents the architecture module.
- Use the new DFD as a base to model the essential system of the architecture module with DFDs, PSpecs, CFDs, and CSpecs with their STDs and Decision Tables.
- Same as step 2 for the new subsystem.
- Same as step 3 for the new subsystem.
- Same as step 4 for the new subsystem.
- Same as step 5 for the new subsystem.
- Same as step 6 for the new subsystem.
Repeat these steps for each architecture module and for each level as needed.
The methods are described in Strategies for Real-Time System Specification (1987), and in System Development - A Practical Guide (1997), both published by Dorset House.