FMEA: Quality Assurance Methodology
| DOI | https://doi.org/10.1108/02635579010002046 |
| Pages | 21-23 |
| Date | 01 July 1990 |
| Published date | 01 July 1990 |
| Author | Janet Webber |
| Subject Matter | Economics,Information & knowledge management,Management science & operations |
FMEA:
QUALITY ASSURANCE METHODOLOGY
21
FMEA: Quality
Assurance
Methodology
Janet Webber
F
MEA techniques ensure total customer
satisfaction and also save lost production
capacity.
Introduction
Involving the customer, outside toolmaker and raw material
supplier as well as its own quality and production personnel
in computerised Failure Mode and Effect Analysis (FMEA)
has enabled injection moulders Davart Plastics to reduce
wastage and achieve exceptionally high quality standards.
Davart Plastics' quality manager, Steve Keller, explains:
Failure Mode and Effect Analysis turns quality assurance
into
a
before-the-event action not an after-the-fact exercise.
However, the component supplier may not always be aware
how critical certain aspects of a design are, nor of the
problems they pose to his toolmaker. Bringing all parties
together to analyse the problems using the logical
methodology of a computerised FMEA program quickly
identifies causes and points to solutions.
Instead of each company or department completing its
task before passing it to another, the team acts with
cohesion.
Davart uses an FMEA software program from the
Halesowen Microcentre, a computer systems and training
house within Halesowen College in the West Midlands,
and has found it a consistent, cost-effective and objective
means of obtaining hard facts.
Before a new part goes into production, an FMEA team
is convened consisting of Davart Plastics quality manager,
a technical sales engineer, the production manager,
toolmaker and raw material supplier. If appropriate, the
customer is also invited to participate.
First, all possible ways in which a part or assembly could
fail to conform to the released engineering requirements
or to specific process criteria, are identified using the
simple methodology of the Halesowen Microcentre
software. "We start with the assumption that failure
could
occur and our objective is to establish how and then,
regardless of engineering specifications, what the
customer would find objectionable", says Steve Keller.
The possible failures are, therefore, analysed according to:
• the effect on the customer;
• the seriousness of this effect;
• the potential cause of the failure;
• how frequently it is likely to occur;
• the probability that it will be detected by existing
quality checks.
Typical failures in injection moulding can be distortion,
poor clipping, discolouration, blistering, ejector marks, dirt
or bad finish, with effects ranging from unacceptable visual
standards to failure to fit into the assembly.
One company has found FMEA
a consistent, cost-effective and
objective means of obtaining
hard facts
The severity of the effects is estimated on a scale of 1
to 10: 1 indicating no effect on the customer through to
10 indicating failure to meet safety legislation.
Every possible cause is then assigned to each failure.
Without computer aid, this would involve an enormous
clerical input which in the past has caused manual FMEA
techniques to flounder. Typical injection moulding failure
causes include incorrect feed, tooling or melt temperature
on to damage in handling or inadequate packaging.
Each failure mode is ranked 1 to
10
according to how likely
it is to occur. If a similar process is under Statistical
Process Control, then these statistical data can be used
to provide the ranking.
Next the software prompts for current controls that could
prevent the failure occurring to be assessed on the same
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