What is Failure Mode and Effect Analysis ( FMEA )
FMEA is an analytical technique that combines the technology and experience of people in identifying foreseeable failure modes of a product or process and planning for its elimination.
FMEA is a “before the event” action requiring a team effort to easily and inexpensively alleviate changes in design and production.
- Design FMEA
- Process FMEA
- Reliability is one of the most important characteristics of any product, no matter what its application.
- It is also an important aspect when dealing with customer satisfaction, whether the customer is internal or external.
- Customers want a product that will have a relatively long service life, with long times between failures.
- Reliability may be defined as the probability of the product to perform as expected for a certain period of time, under the given operating conditions and at a given set of product performance characteristics.
Types of failures:
iii. Wear out
Debug- includes a high failure rate at the initial stages because of inappropriate use or flaws in the design or manufacturing.
Chance-is the failure of the product due to accidents, poor maintenance or limitations on the design.
Wear out-covers failure after the product or process has performed as expected for at-least the time given by the manufacturer as the product or process life. A successful design or product should ideally fail only in this last method.
Intent of FMEA:
- When acquiring new machines, creating a new product or even modifying an existing product, it is always necessary to determine the product or process.
- One of the most powerful methods available for measuring the reliability of the process or product is FMEA.
- FMEA can be implemented both in design and process areas as it basically involves the identification of the potential failure modes and the effect of those on both the internal and external customers.
- FMEA attempts to detect the potential product related failure modes.
- The technique is used to anticipate the causes of failure and prevent them from happening.
- In order to make FMEA as successful, it is extremely important to treat the FMEA as a living document, continually changing as new problems are found and being updated to ensure that the most critical problems are identified and addressed quickly.
- One purpose of FMEA is to compare the design characteristics relative to the planned manufacturing or assembly methods to make certain that the product meets the customer requirements.
- Corrective action should begin as soon as failure mode is identified.
- Consumers today are far more particular than they have been in the past, demanding products of the highest quality for the lowest possible cost.
- FMEA also allows the engineer to keep a record of all thoughts and actions taken to ensure a safe and reliable product.
- The FMEA methodology is a team effort where the possible engineer involves assembly, manufacturing, materials, quality, service, supplier and the customer.
- The team leader has certain responsibilities, which include determining the meeting time and place, communicating with the rest of the team, coordinating with the rest of the team, coordinating corrective action assignment and follow-up, keeping files and records of FMEA forms, leading the team through completion of the forms, keeping the process moving and finally drawing everyone in to participation.
- There also should be a recorder who records the results on the form and distributes to participants in a timely manner.
Stages of FMEA:
There are four stages of FMEA
- Possible Failure Modes
- Root Causes
- Probability of Cause
- Severity of Effect
- Effectiveness of Control to Prevent cause
- Risk Priority Number
Correcting High Risk causes
- Prioritizing Work
- Detailing Action
- Assigning Action Responsibility
- Check Points on completion
Re-evaluation of Risk:
Recalculation of Risk Priority Number
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