HIRARC: FMEA

FMEA is an acronym that stands for Failure Modes and Effects Analysis. It can identifies the potential failure of a system and its effects, assesses the failures to determine actions that would eliminate the chance of occurrence and documents the potential failures.

It’s oriented towards equipment rather than process. Particularly suited for mechanical and electrical systems. FMEA systematically in identifies the consequences of component failure on that system and to  determines the significance of each failure mode with regard to the system's performance. It will improve the safety, Quality and Reliability.

The purpose of this Hazard Identification system are to identify single equipment of system failure modes and the potential effects or consequences of the failure modes on the system or plant, AND to generate recommendation for increasing equipment or system reliability, thus improving process safety.

Resource requirements to do this system are;(1) Technical drawing of the equipment / system,(2) Knowledge of equipment function and failure modes,(3) Personnel with knowledge of system /plant function and responses to failure equipment failure AND (4) Personnel with knowledge of FMEA methodology and analysis.

It also can be define as the extent of the system to be analyzed. It usually performed in relatively small steps. It requires analysts / personnel with a knowledge of the system. It will show the functional relationships of the parts of the system and their performance requirements.

Level of Analysis are based on the functional structure of a system and the failure modes are expressed as failure to perform a particular subsystem function. Primary function is that for which the subsystem was provided and secondary function is one which is merely a consequence of the subsystem's presence.

It will be use to analyze Failure modes of  premature operation, failure to operate when required, intermittent operation, failure to cease operation when required, loss of output or failure during operation, degraded output and etc. It will looks at the likely causes and the effects on both the components and the system, consideration is given to the relative importance of the effects and the sequence AND safeguards against such failures and methods of detecting them are then examined.

Reporting of FMEA are to identify the most significant failures in terms of their effects on the overall system, decide whether or not the existing safeguards and detection devices are adequate AND more detailed analysis on the ‘weak link’. There are no standard reporting format; typically covers  The unit/system, Failure mode, Consequence of failure, Symptoms, safeguards and Corrective action.

 

FMEA CRITICALITY ANALYSIS (FMEACA)

Criticality is defined in the same way as risk – that is, a combination of the severity of an effect and the probability or expected frequency. It is the simplest approach that requires a form of ranking or quantification in effect / consequence AND frequency.

Effects are normally ranked into one of the following categories; (1) loss of mission due to inability of equipment to perform,(2) economic loss due to lack of output or function, (3) damage to plant or third party property, (4) injury to operating personnel or the public, (5) death to operating personnel or the public and/or significant damage to the environment.

Quantification of frequency depends on the data available and may again be a simple ranking, such as one depending on failure probability during the operating time interval, for example; extremely unlikely, remote, Occasional, reasonably frequent AND frequent.

Alternative ranking for effect (reverse order or severity), For Example; (1) catastrophic - may cause death or total system loss,(2) critical- may cause severe injury or damage,(3) major - may cause some injury or damage AND (4) minor - requires unscheduled maintenance.

Corrective Action And Follow-up are (1) reduce probability that the cause of failure will result in the failure mode,(2) reduce severity of failure by redesign or add protection redundancy AND (3) increase probability of detection.