Guidelines for writing IVHM requirements for aerospace systems
A rough outline of the document is as follows:
1. Introduction to IVHM and rationale for the document
2. Identification of different (internal and external) stakeholders. Customers, maintenance personnel, sales and marketing and finance. Systems designers, RM&S experts, etc. Need to link requirements to design rationale, including a cost-benefit-analysis.
3. Requirements breakdown structures, from high level system requirements to lower level sub-system requirements, and finally down to component specifications.
4. Links to other systems engineering processes such as V&V, architecture design, program milestones, etc.
5. Examples of good and bad requirement practices. Maybe individual case studies or an example of an entire system.
Rationale: Integrated Vehicle Health Management (IVHM) systems are increasingly being designed and incorporated on different aerospace platforms but very little guidance exists for the systems engineering aspects of IVHM design. It is probably because of this that designers have to use knowledge picked up exclusively by experience rather than by established process. For example, we have seen many examples of designers not identifying the right stakeholders, articulating customer needs, linking top level requirements to the design rationale including a cost-benefit-analysis, breaking these down to lower level requirements, and finally developing the links to other systems engineering processes such as V&V, architecture design, program milestones, etc. IVHM systems have unique challenges that require the designer to look beyond their own field and consider the constraints and specifications of other interlinked systems. We believe that there is a strong need to author a document that gives working engineers and program managers clear guidance on all the elements of IVHM that they need to consider before designing a system.