A FMEA is a bottom-up approach to analyzing system design and performance. To begin a FMEA, a particular level of a system is analyzed. This can be at the component level (referred to as a piece-part FMEA) or at a higher level (referred to as a functional FMEA). For each lowest level, a list of potential failure modes is generated. Effects of each potential failure mode are then determined.

For example, perhaps you are performing a piece-part FMEA on a computer monitor. One component in that computer monitor is a capacitor. Assume that the capacitor has two potential failure modes, which are that it can fail open or fail short. If the capacitor fails open, the effect might be that the monitor displays only wavy lines. If the capacitor fails short, the effect might be that the monitor is completely blank. In this case, the failure mode where the capacitor fails short and causes the monitor to go blank might be considered more severe or critical than the failure mode where the capacitor fails open and the monitor displays only wavy lines. Consequently, you attempt to either find ways to prevent failures from occurring or lessen their criticality when they do occur.

A FMEA can use failure rate calculations that are performed during the reliability prediction portion of an analysis to determine the probability of occurrence. Failure rate is a value describing how often a component or assembly fails. In a FMEA, you can use failure rates to compute mode criticality, which is the probability that a particular failure mode will occur. When criticality is considered, a FMEA is sometimes called a FMECA (failure mode, effects, and criticality analysis).

Like prediction calculation models, FMEAs are based on standards. Three basic types of FMEA standards exist. First, there are military standard, such as MIL-STD-1629. Second, there are automotive standards, such as SAE J1739. Lastly, there are general standards, such as SAE ARP5580. The FMEA module supports all of these widely accepted standards. For more information, see Windchill FMEA.