Mode & Effects Analysis
- Failure Mode & Effects Analysis
What is an FMEA?
Failure Mode & Effects Analysis was first introduced in the
aerospace industry. It has since become a vital tool to identify
components of concept, design or process steps. A list of the
potential failures associated with these steps, the possible
effects and causes of the failures, and the ability to detect
them are determined and rated numerically.
The steps to completion involve a systematic approach to
recognizing and evaluating all possible potential
failures of a product, process or service. Actions must be
identified to eliminate or minimize the cause (best option) or
the failure mode.
Mode & Effects Analysis needs to be completed in a timely
fashion to ensure successful implementation of actions. The FMEA
must happen as a "before-the-fact" proactive technique
rather than an "after-the-fact" reactionary must.
Who is involved in FMEA?
The development of a Failure Mode & Effects Analysis should
be the responsibility of those involved in the various stages
of, as well as anyone else with insight into, the product,
process or service.
Types of FMEA
Concept FMEA - looks at system options and helps estimate
whether a concept can achieve its desired level of performance.
Design FMEA - looks at design requirements and their
alternatives and ties them into the initial design for
manufacturing and design for assembly.
Process FMEA - looks at new manufacturing and assembly processes
and anticipates potential process failure modes, their effects
- Measurement System Analysis
What is Measurement System Analysis?
When identifying sources of variation, one must take into
account the 5M's and 1P. They stand for Machine,
Method, Material, Measurement, and People.
Time and effort are spent on all the sources of variation but
often the Measurement System is overlooked.
A quantitative evaluation of the gauges, operators, methods of
data collection, etc. used in make numerical observations falls
under the banner of a Measurement System Analysis
The main reason that an MSA is performed is to ensure that the
data collected is a true representation of the process(es) it
has been taken from. There is no room for the GIGO Syndrome
(Garbage In, Garbage Out).
of MSA (1)
- the larger of the apparent and effective resolutions for
single reading systems. A discrimination ratio
which describes how many classifications can be reliably
distinguished given the observed process variation.
- the difference between the observed average of measurements
and the master average of the same parts using precision
- the amount of total variation in the system's bias over time
on a given part or master part.
- the difference in the bias values of a gauge through the
expected operating range of a measuring instrument (gauge).
- variation in the average of the measurements made by the same
"measurer" using the same measuring instrument when
measuring the identical characteristic on the same part(s).
term repeatability refers to the inherent variation of
the measuring system, which occurs when repeated measurements
are made of the same item under absolutely identical conditions
(i.e. same operator, same setup, same units, same environmental
- variation in the average of the measurements made by different
"measurers" using the same measuring instrument when
measuring the identical characteristic on the same part(s).
term reproducibility refers to the inherent variation
occurs when measurements are made under different conditions,
holding all factors constant, and varying only one of either
different operators, different setups, different units,
different environmental conditions, or different measurement
(1). Taken from Measurement System Analysis - Reference
Manual 2nd. Edition, February 1995
Note: Typically, repeatability and reproducibility are
the two major components of the measurement system analysis that
are focused on more than the others. Reference is made to them
as the Gage R&R.
Lean involves the elimination of waste. Sources contributing to
waste can come from methods, materials, machines, measurement or
the actual personnel, to name a few. Minimizing waste from one
or more of these sources optimizes the returns of the
organization, in the form of better quality and increased
productivity. But this is not a new concept.
Lean involves tightening the purse strings. The task becomes one
of not disrupting the quality of the product, process or
service. Only this way will a company be able to continue in
this competitive day and age.
As a company strives toward lean concepts, the benefits soon
become obvious. The organization is able to withstand economic
as well as competitive pressures, without sacrificing quality
and service. The bottom line will be satisfied customers and a
is involved in Lean?
Lean concepts should, like most quality initiatives, involve all
areas of an organization. This will insure that everyone is
working toward the goals of lean concepts.
Fundamentals of Lean
Lean concepts incorporate three elements. These are: Visual
Control, Visual Display, and 5 S (Sort,
Stabilize, Shine, Standardize, Sustain).
It also utilizes the techniques of Kaizan and error proofing (Poka
What is Reliability?
Customers are the ones who define what quality is - based on
their expectations. They want products and services that will
meet or exceed their needs and expectations throughout the
expected life of the product or service, at a cost they can
afford. Reliability is related to the ability of a product or
service to perform its desired function for a given life span,
and under the operating conditions encountered in a manner that
meets or exceeds customer expectations.
The focus is on the probability of maintaining the intended
function over time, and is typically measured as a percentage.
The measurable are related to the probability of failure in a
test or field run. Tied into the measurable is the customers'
perception. This perception must then be converted into
understandable engineering terms. From this point on, the time
to failure can be successfully determined.
After analysis and diagnosis of the reliability components,
requirements need to be defined. From this point on, robustness
needs to be designed into the process. Upon completion of the
design for robustness, there must be some form of verification.
This would lead to sustaining the gains and improving the
quality of the product, process or service.