Functional Chain Analysis
Functional Chain Analysis (FCA) is the process by which coherency of end-to-end functionality can be assessed, understood, and assured. The primary purpose for undertaking a Functional Chain Analysis is to explore potential integration weaknesses prior to faults appearing during Integration, Testing or Operations. Failing to understand the complete Functional Chain and the potential failure could result in dangerous situations and / or costly downtime.
Typically, Functions are formed from multiple layers of Sub-Functions both virtual and physical, utilising real world data in the form of "Inputs" integrated to enact a specific operation resulting in "Outputs". Both the Inputs and Outputs can be in many forms depending on the beginning and end of the Functional Chain being analysed. To really gain benefit from Functional Chain Analysis, a risk-based assessment of the Functions and Sub-Functions within the chain can be utilised to target specific areas of most concern, either due to complexity, severity of failure or limitations of knowledge.
Using a Top-Down approach, assessing the chain of events, to develop an understanding of the severity of a resulting action (or inaction) due to weakness or failure of a functional chain provides opportunities to mitigate an undesirable outcome during the design phase. Functional Chain Analysis also supports the generation of Verification Evidence in support of Assurance or Certification Packs.