8.6.1 Integrating Failure Modes and Effects with the System Requirements Analysis

Abstract

Assessing failure modes and effects as part of the system requirements analysis activity provides specific benefits. Using the concept of functional failure, the requirements analyst, whose primary focus is system functionality, can address the failure of any identified function to be performed as part of the functional analysis. The requisite behavior is documented as a new route to an existing function, or may be a new function altogether. Such integration reduces rework later in the program, since all conditions (nominal and fault) can be identified while requirements are being formulated, well ahead of integration testing. We find also that focusing on conditions associated with requirements stimulates better requirements analysis and documentation, leading to better implementation by designers. In addition, identifying all functional failure modes and their effects during the requirements analysis activity allows the requirements analyst to verify requirements completeness. This provides a management metric for measuring completeness of the requirements analysis process.

9.5.1 Functional Architecture's Mental Roadblocks and Other Things Your Mother Didn't Tell You

“…The same type of analysis can be performed at the architectural level by looking at the failures of architectural level components, even if the specific part has not been defined. Functional failure analysis takes this one step earlier and asks how a system will perform if a function does not behave properly (Spangler, 1994;Armstrong, 1995;Carson, 1996 and2004). Figure 11 provides an example of considering a situation that could bring the system to a stop.…”