Failure modes and effects analysis (FMEA) is a systematic technique intended to recognize and evaluate the potential failure of a product or process, and the effects of that failure. It is also intended to identify actions that could eliminate or reduce the chance of the potential failure. It involves the recording and analysis of actual and potential problems with a product design or process, along with the related solutions. This information makes it possible to improve accountability, avoid repeated mistakes, and improve the quality of the end product.
FMEA data is maintained as general FMEA information, with the FMEA function at the top level. If the user wishes to have design FMEAs, he creates a design FMEA header for a Product Structure or Recipe Structure Alternate. If the user wishes to have process FMEAs, he creates a Process FMEA header for a routing alternate. The user can define new FMEA failure (and lower level) information for these headers, or use existing general FMEA data.
The process FMEA header serves as the connection between a routing alternate and a generic FMEA function. FMEA functions can be linked to multiple FMEA headers for different parts, structure types, or even to design FMEA headers. The design FMEA header serves as the connection between a structure alternate and a generic FMEA Function.
FMEA functions can be linked to multiple FMEA headers for different parts, structure types or even to process FMEA headers. In IFS Applications, each product structure alternate, recipe structure alternate, or routing alternate performs one or more intended functions. The FMEA function is defined as a functionality that the part is to perform or as an important attribute the part has. For example, it could be a requirement to fall within a specific temperature range, the dimensions of the item, foot-pounds of torque, or a more general thing like the asthetic appearance of the part.
Each function can have one or more failures. These are conditions that prevent the product or process from performing as intended. An FMEA failure is a problem, failure, or shortcoming based on an FMEA function. An FMEA failure represents a problem in the part or in the process to make the part.
An FMEA failure has two elements; FMEA Causes and FMEA Effects. The FMEA cause is the details about how the FMEA failure was caused to happen; there may be one or more FMEA causes for an FMEA failure. An FMEA cause has an occurrence level. The problems that happen more often have a high occurrence level, while very rare problems have a low occurrence level.
The FMEA effect is the details about the effects the FMEA failure will have on the part, in the making of the part, or on the end user. This includes information about the severity of the FMEA effect. An FMEA effect that causes bodily harm to the end user would be very severe, while an FMEA effect that manifests itself as a slight smell would be a minor to moderate severity.
The FMEA causes have details of their own. They are FMEA Controls and FMEA Recommended Actions. Also each cause can have one or more controls. These are mechanisms that detect the failure and/ or its effects before they reach the customer.
FMEA controls detail the detection, inspection, or remediation mechanisms used to detect (and possibly avoid) the FMEA failure. There could be many possible controls. Each FMEA control has a detection rating, which indicates how likely that FMEA control is to detect the problem. A high detection rating would represent a poor chance of detection, while a low detection rating would represent a good chance of detection.
FMEA recommendations are a list of possible actions, process changes, or activities that could be used to make the FMEA Failure less common, reduce the severity of the FMEA effect, or make it easier to detect the FMEA failure. These recommendations may or may not be acted upon; those that are, will have FMEA actions associated with them.
The user may wish to use a graph to determine which FMEA problems are most likely to require immediate attention. The FMEA Analysis Graph plots the risk priority number (RPN) against the severity for all defined causes. The graph is a traditional quadrant graph; those FMEA causes that plot in the upper right quadrant have high severity and RPN values and are the most important, while those in the lower right quadrant are less important.
Using this data, you can prioritize the problems with a product or process, taking into account their likelihood and the severity of each occurrence. This allows you to decide which problems require immediate action and which can be ignored. Once you decide on the appropriate controls, you can do further analysis to assess their effectiveness.