Reliability

Ability to prevent failures on a system and a product is the indicator of reliability of the process. Reliability is a key element of a production process that ensures both the production line and the resulting product is existing in the desired state. This element of reliability is created and maintained by the meticulous work of reliability engineering agents such as engineers overseeing the process, maintenance and production personnel.

Concept of reliability is implemented in two distinct forms as proactive and reactive reliability. Proactive reliability relies on foreseeing possible failures and taking appropriate precautions to prevent the occurrence of the failure. Reactive reliability is more of a failure management approach where failures are addressed and eliminated after they come to existence.  A state of ideal reliability is created by detecting and eliminating any possible failure before any occurrence through proactive reliability. Achieving such forecasts for a productive reliability application is possible through conduction of failure analysis. 

FMEA

A Failure Modes and Effects Analysis (FMEA) is often one of the first steps you would undertake to analyze and improve the reliability of a system or piece of equipment. FMEA is a failure analysis method where every component, assembly and subassembly of a system is observed and studied to determine any possible failure each component might face. Each element is analyzed for its failure modes and impacts of such failures on the whole system. 

In order to evaluate the risk level and the required precautions, assessed elements are given ratings on probability of occurrence, severity of the failure and detection method.

Probability:

In order to give a component a probability rating analysis,FEM calculations, literature research and comparison to previous failures.

Ratings and their meanings are as such:

RatingMeaning
1Extremely unlikely (virtually impossible or No known occurrences on similar products or processes, with many running hours)
2Remote (relatively few failures)
3Occasional (occasional failures)
4Reasonably possible (repeated failures)
5Frequent (failure is almost inevitable)
Table 1: Probability Rating Criteria

Severity:

In order to give a component a severity rating user has to study the expected and experiences. 

RatingMeaning
1No relevant effect on reliability or safety
2Very minor, no damage, no injuries, only results in a maintenance action (only noticed by discriminating customers)
3Minor, low damage, light injuries (affects very little of the system, noticed by average customer)
4Critical (causes a loss of primary function; loss of all safety margins, 1 failure away from a catastrophe, severe damage, severe injuries, max 1 possible death)
5Catastrophic (product becomes inoperative; the failure may result in complete unsafe operation and possible multiple deaths)
Table 2: Severity Rating Criteria

Detection Method: 

The ability and the method of detection for a possible failure is another important aspect of FMEA. Components are assessed according to the ease of failure detection.

RatingMeaning
1Certain – fault will be caught on test –
2Almost certain
3High
4Moderate
5Low
Table 3: Detection Method Rating Criteria

Additional Assessment Criteria:

Potential failure mode , potential cause, mission phase, local effects of failure, next higher level effect, system-level end effect, detection dormancy period, actions for further investigation are all categories of information needed for a complete FMEA.

Impact of Sensemore in Reliability Applications 

Solutions developed by Sensemore enables their users to monitor the health of their machinery , constantly keep conditions under supervision, detect and classify different operation and failure modes , predict possible malfunctions before the occurrence and provide a higher level of failure detection ability. 

For FMEA applications, Sensemore solutions provide a great advantage by constantly gathering data about the operation regime, failure modes, root causes of malfunctions and many different types of data such as vibration , temperature, current, voltage etc.. By distinguishing different operation and failure modes Sensemore products enable a more precise assessment for the probability rating part of FMEA. Also through the higher perception power Sensemore products provide their users, rating indicating the difficulty of fault detection is decreased.

Through predictive maintenance and condition monitoring applications such as Sensemore products, conducting proactive reliability analyses such as FMEA is easier and more accurate.