Failure mode and effects analysis (FMEA) is a systematically progressing method for dependability analysis that was developed in the late 40's by US military. The basis of the analysis is to try to recognize all of the possible failure events, aka. failure modes, affecting parts in the lowest levels of the system. Each recognized failure mode is evaluated locally and also based on the consequences it causes to the system. During the analysis the failure modes with the most significant consequences will be assessed some methods to prevent the failure or to lower the effect of the consequences, if possible.
FMEA can be expanded to Failure mode, effects, and criticality analysis (FMECA) by defining criticality for the significance of the failure mode effects. The criticality of the failure mode effects consists of failure severity, detection and occurrence frequency. Criticality describes the effect of the failure mode for system performance.
FMECA method is used as a tool to prevent potential system failures before they occur. When using FMECA in the design phase it is possible to affect the final safety and reliability factors of the system in a cost-effective manner. FMECA can also be used with operating systems to develop their safety and overall operations.
Essential parts of FMECA are different block diagram or fault tree models that can be used to describe the system structure and relations between different parts of the system all the way from the component level to the system level. The main purpose of the analysis is to show and classify the cause-consequence relations between failure modes and functional failures. FMECA can be added as a part of more extensive RCM analysis or it can be used as an individual reliability analysis.
FMECA tries to answer the following questions:
- What can fail?
- What is the effect of the failure?
- How probable is the failure?
- What are the consequences of the failure?
- What can be done to the failure?
- How can the causes of the failure be removed?
- How can the severity of the failure be decreased?
FMECA method can be used e.g.
- to make sure that all potential failure modes and their effects are taken into account to ensure undisturbed operation of the system
- to recognize all the potential failure modes and to estimate the criticalities of their effects
- to show the cause-consequence relations of each failure mode
- to guide the selection between different design solutions and to choose the ones that have the most significant effect on relaibility and safety
- to provide information for the maintenance planning
- to provide information for quantitative reliability and dependability analysis
Ramentor has added a solid FMEA section to the ELMAS software. Therefore ELMAS offers the traditional FMEA tool in the same package together with other supporting modeling and simulation qualities. This gives a totally new perspective for the use of FMEA method.
Read more about Ramentor's FMEA solution >>