In this dynamic of exploring the contours of the "maintenance
tools", here is an overview that allows to discover the FMECA method from
its origin to its industrial objective.
FMECA: Failure Mode, Effects and Criticality Analysis
Where does FMECA come from?
What about the objectives of the FMECA?
It consists in:
l
Identifying the causes and
effects of the potential failure of a process or a means of production
l
Identify the actions that can
eliminate (or at least reduce) potential failure.
It consists in imagining the dysfunctions leading to the failure
before they occur and is therefore essentially a predictive method.
The different types of FMECA
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Process
We identify the failures of the manufacturing process whose effects
act directly on the quality of the manufactured product (failures are not
considered).
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Medium
We identify the failures of the means of production whose effects
act directly on the productivity of the company. It is therefore the analysis
of failures and the optimization of maintenance.
l
Safety
This type aims at reducing the risks related to the use of a means
of production.
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Design
It is carried out during the design of a production tool.
l
Product
It analyzes the impact of the failures of a product on the use that
a customer makes of it.
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Organization
It applies to the different levels of a system and includes the
management system, the information system, the production system, marketing,
HR, finance, and all levels of the organization.
Application of the FMECA
Within a company, the use of FMECA results in:
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An optimized production, the
right product the first time
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A permanent improvement of the
means of production to limit failures.
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A constant improvement of the
organization
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The setting of a quality threshold
to be obtained, and the implementation of the means to reach it.
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An analysis of each production
defect
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The drafting of recommendations
in case of failures
Five (5) steps to implement the FMECA method.
1.
Set up a working group.
This is a demanding study. The participants will have to be
seriously involved and given the necessary time to correctly carry out the part
of the study they oversee. It is important to consider this aspect at its true
value and to clearly define the role of each person, their contributions, while
considering their skills and availability, the
clarification of the purpose of the study, its scope, its reach. Its expected objectives will be stated concretely and in accordance with the needs of the sponsors of the study and the participants in its implementation. This is also an opportunity to specify the process to be followed.
2. Carry out a functional analysis of the process (or the machine): Functional
breakdown.
As its title clearly indicates, it is a question of listing and relating all the functions of the product or the phases of the process to identify the causes of potential dysfunction.
3. Analyze the potential failures: Identification of potential
failures
This is a rational study of potential failure modes, causes and
effects. The success of this third step is directly dependent on the care given
to the functional breakdown. It requires a broad participation of all the
people likely to bring a lesson most often resulting from their own experience.
Evaluate these failures and determine their criticality.
4. Evaluate these failures and determine their criticality
The evaluation is done according to three (3) main criteria:
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Severity: It expresses the
importance of the effect on the quality of the product (process) or on the productivity
(machine) or on the safety (safety).
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The frequency: It is estimated
the period during which the failure is likely to occur again.
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Non-detection: It expresses the
efficiency of the system to detect the problem.
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The criticality: When the 3
criteria have beeń evaluated in a line of the FMECA synthesis, the product of
the 3 scores obtained is made to calculate the criticality: C = G * F * N
5. Define and plan actions
- Preventive actions: we act to prevent the failure before it
occurs, to prevent it from
happening. These actions are planned. The period of application of
an action result from the evaluation of the frequency
modifications of the means of production intended to eliminate the
problem. The cost of this type of action is not negligible and it is treated as
an investment.
- Action plan
- Designation of a person responsible for the action
- Determination of a deadline
- Determination of a budget Review of the evaluation after
implementation of the action and feedback of the results
To conclude, The FMECA is a prevention method applicable to any system. This method must be part of a global approach and it is a way to prevent certain failures and to study the causes and consequences. It is a tool that can help in the implementation of certain standards, including the ISO 9001 version 2015 in the “Design Control” section.
