FMEA can provide an analytical approach, when dealing with potential failure modes and their associated causes. When considering possible failures in a design – like safety, cost, performance, quality and reliability – an engineer can get a lot of information about how to alter the development/manufacturing process, in order to avoid these failures. FMEA provides an easy tool to determine which risk has the greatest concern, and therefore an action is needed to prevent a problem before it arises. The development of these specifications will ensure the product will meet the defined requirements and customer needs.
Types of FMEA:-
Process: analysis of manufacturing and assembly processes,Design: analysis of products prior to production,Concept: analysis of systems or subsystems in the early design concept stages,Equipment: analysis of machinery and equipment design before purchase,Service: analysis of service industry processes before they are released to impact the customer,System: analysis of the global system functions,Software: analysis of the software functions
A failure mode is given occurrence ranking (O) ranging from 1–10. Actions need to be determined if the occurrence is high (meaning > 4 for non-safety failure modes and > 1 when the severity-number from step 1 is 1 or 0). Occurrence also can be defined as %. If a non-safety issue happened less than 1%, we can give 1 to it. It is based on your product and customer specification.
A failure effect is defined as the result of a failure mode on the function of the system as perceived by the user. In this way it is convenient to write these effects down in terms of what the user might see or experience. Examples of failure effects are: degraded performance, noise or even injury to a user. Each effect is given a severity number (S) from 1 (no danger) to 10 (critical).
The assigned detection number measures the risk that the failure will escape detection. A high detection number indicates that the chances are high that the failure will escape detection, or in other words, that the chances of detection are low.
RPN = O X S X D
This app will help you to prepare fmea worksheet for each item/product/function.The work sheets can be saved ,retrieved and edited.