The two most common types of FMEAs are Design-FMEAs or DFMEAs and Process-FMEAs or PFMEAs. Similar principles and steps are followed for both Design and Process FMEAs.
The primary objective of a Design-FMEA is to uncover potential failures associated with the product design that could cause:
- Product malfunctions
- Shortened product life
- Safety hazards while using the product
Design-FMEAs should be used throughout the design process – from preliminary design until the product goes into production.
Process-FMEAs uncover potential failures that can:
- Impact product quality
- Reduce process reliability
- Cause customer dissatisfaction
- Create safety or environmental hazards
Ideally, Process-FMEAs should be conducted prior to start-up of a new process, but they can be conducted on existing processes as well.
Design-FMEAs Naturally Feed Into Process-FMEAs
It makes sense that a DFMEA has a natural link to a PFMEA conducted on the process that will be making the design/product. Typically, such linked FMEAs would be conducted by different teams and sometimes, depending on who is actually making the design, the PFMEA could be conducted by a different company if the product will be made in a different operation than where it was designed.
Other Types of FMEAs
FMEA-MSRs – Supplemental FMEAs for Monitoring and System Response have been introduced as part of the 2019 AIAG-VDA FMEA guidelines. This unique FMEA is done in addition to a DFMEA not in place of it. FMEA-MSRs focus on potential failure causes that might occur when the customer is operating the product. The effects of the failure causes on the system, vehicle, people and regulatory compliance are considered in terms of whether the failure causes or failure modes will be detected by the system or whether the failure effects will be detected by the driver/operator.
System-FMEA – System-FMEAs (SFMEAs) are used to analyze a compilation of subsystems. The focus of SFMEAs is on system-related deficiencies such as: Integration, interactions, interfaces between subsystems; Interactions with the immediate or adjoining surroundings; Interactions with workers; system safety considerations.
Machinery FMEA – Machinery-FMEAs (MFMEAs) are used to assess and increase reliability of the machinery. MFMEAs can lead to the incorporation of failure prevention measures, automated fail-safe shutdown techniques to minimize either equipment damage or product defects and the reduction of both planned and unplanned downtime.
Software FMEA – Software-FMEAs (SW-FMEAs) study the programming logic that goes into generating reports or controls associated processes. A Software-FMEA can be conducted on software under development or existing software already in use.
Service FMEA – A Service-FMEA is conducted on transactions. Since a transaction is actually a process, PFMEA techniques are used. Obviously, some of the rating criteria for Severity and Detection must be customized so that it applies to transactions.