System and Safety Analysis
The analysis of a system during development of a custom electronics solution focuses both on the ability of the system to deal with random hardware failures and for the development process to eliminate systematic sources of error. While the broader system analysis may look at other engineering disciplines such as heat transfer, computational fluid dynamics, or finite element analysis, Pi Innovo focuses on various failure mode analysis techniques.
Pi Innovo directly participates in conceptual design of control systems, especially in projects where a completely new type of system is being developed for the first time. Domain experience with combustion, hydraulics, E&M, vehicle dynamics, aviation, and other niche topics is native to various Pi employees, and is critical for creating and analyzing new concepts for control systems. In many cases, Pi Innovo gives design input and review feedback for system components separate from the ECU, such as hydraulic schematics, mechanical systems, and wire harnesses. System use cases, software storyboards, and other concept of operations documents are used to capture the system fundamentals during this stage.
The ISO 26262-3 process of evaluating a system for its hazards and ranking the hazards on a severity scale is a powerful analysis tool used by Pi. The HARA, or hazard analysis and risk assessment, is a process commonly found in ISO 26262 based projects. Even for non-ISO 26262 projects, the HARA process is an effective systems engineering analysis technique to ensure functional safety.
A design failure modes and effects analysis (DFMEA) is a top-down inductive analysis technique well suited to looking at the response of a system/sub-system/component to a failure input. Pi Innovo starts the DFMEA process by doing a careful analysis of the boundary of the system under analysis. This is described in diagram form within the DFMEA template.
The Fault Tree Analysis (FTA) is a bottom-up deductive analysis technique. The FTA and DFMEA complement each other in that they approach the problem from opposite directions. The fault tree analysis starts with the development of the top-level events. The selection of the top-level events for doing the system level (aka vehicle level) FTA is best considered from the safety goals, operational goals, and system requirements. These simple benign statements when inverted form a good basis for the top-level events.