In either Top Down or Reverse Engineering, the design traceability and elemental analysis (from DO-254 Appendix B) ultimately provide the evidence of completion for this task.

• Requirements Decomposition Prerequisites
• System Level Functional Requirements complete and baselined
• System Design Constraints
• Requirements Decomposition Objectives
  • Complete decomposition of System Level Requirements into Hardware Requirements. Decomposition implies that the newly developed requirements are traceable to the System Level; the requirements traceability will be the verification that this task is complete.
  • Capture of design specific Derived Requirements as needed to fully define the functions and performance. Derived Requirements are defined as requirements that will not fully trace up to the system level. Examples of the types of requirements that may fall into this category are:
    • Design Margins (Typically included in the decomposed and derived requirements as well)
    • Production and Maintenance interfaces
      • Layout Constraints (Including floor planning in FPGA/ASIC designs)
      • Nodal Accesses
    • Testability
    • Robustness

Obtain the full DO-254 Reverse Engineering process white paper (8 Steps of Reverse Engineering to show DO-254 Compliance)