The MSR includes an analysis of potential failures that may occur under normal operating conditions and their respective impact on the system. An essential goal of the analysis is to determine if the system or the end user will detect the failure.
The new manual issued jointly by AIAG and VDA containing guidelines for conducting FMEA, in addition to a fairly large revolution in the approach to risk analysis (including withdrawing from calculating RPN as an indicator of risk assessment), also contributes a lot to the process of conducting risk analysis in industry. One of the new products is FMEA-MSR. The purpose of FMEA for Monitoring and System Response (FMEA-MSR) analysis is to identify how systems can fail when used by the end customer. This approach should be used in addition to the DFMEA (or Structural FMEA). FMEA-MSR is to help in maintaining safety and compliance with legal regulations during the use of products by the end customer (driver / passenger).
This new approach covers the analysis of potential failures that may occur under normal operating conditions and their respective impact on the system. An essential goal of the analysis is to determine if the system or the end user will detect the failure if it does occur. This method works great as a fulfillment of hardware and software activities, i.e. for components and systems with embedded software. The approach is combined with HARA (The Hazard Analysis and Risk Assessment) in accordance with ISO 26262 and with ASILs (Automotive Safety Integrity Levels). The MSR is needed in today’s world to ensure the correct collection of car diagnostic data and make this data easy to use for the vehicle user and manufacturer. Cascading information helps to manage possible complaints and returns from the market. Each of these issues will allow you to save money at the stage of product development and its operation.
The risk assessment in this approach consists of 7 stages (analogous to the new approach to DFMEA and PFMEA) and begins with building a tree that takes into account systems and subsystems and their intended and unintended functions. A similar sequence of analysis has long been known from the VDA approach and the VDA 4.2 handbook. If someone cooperated with German customers, the MSR in accordance with VDA is similarly created. Detailed analysis begins with determining the severity level. Here, the table does not deviate from that constructed for DFMEA in the manual and focuses on the user impact. The table supporting the assessment of the occurance frequency contains information on how often the problem occurs or may occur during the use of the vehicle. Occurrence frequency descriptions refer to the intended service life of the vehicle. The evaluation of detection was changed to the evaluation of the criterion related to monitoring (Monitoring criteria). Here you can see the strongest reference to the hardware and / or software of products (products with embedded software). In order to determine the size of this criterion, it is necessary to verify the possibility of detecting the problem by the vehicle system or the user (driver). Another aspect that should be taken into account is, of course, the system response, which is a solution that ensures the desired system response or the appropriate action by the user. Determining individual points gives a chance for a 3-step assessment of the risk level: high, small and medium. The table contained in the manual does not refer in any way to the RPN number, but to the new AP (Action Priority) measure. This gauge shows whether a given defect is well monitored, detected and whether the system / driver responds or is likely to respond / react as intended.
The practical application of the approach to data collection can be noticed in Tesla cars, which can predict a road collision that may occur. This system operation can be seen in the video: https://www.youtube.com/watch?v=N-Qo61z05bg
Author: Daniel Mormul [PROQUAL]