World-Class, Lean Performance in the SMEs - Small and Medium Enterprises - by Carlo Scodanibbio, Industrial & Business Consultant - Lean Management Consultant
scodanibbio.com


Carlo Scodanibbio
Industrial & Business Consultant
Lean Management Consultant

synoptic pages (34)


home     profile     consulting     training     events     contact 

FMEA - Failure Mode and Effect Analysis

Monsters want "reliable" food.
This statement is valid for any kind of product or service. Not only for "technical" products or sophisticated services.
Surely, a motor car breaking down is more serious, in terms of "lack of reliability", than a "difficult-to-open pack of chewing-gum" or a "porter delivering your luggage to your hotel room in a longer time than expected".
Still, in all cases we are considering the consequences of inadequate "reliability".

Reliability is one of the features that have become more and more important over the years.
The new-world enterprise must be conscious of this phenomenon and take adequate actions to assure high or at least adequate levels of reliability in the products or services it offers, and/or in the processes that output products and services.

Various disciplines are available for this purpose. FMEA - Failure Mode and Effect Analysis is one of them, definitely the most recommended for a number of general and specialised applications.

Its comprehensive definition and description sounds like:

".....an analytical technique addressed to identify - already at design stage - critical areas or potential sources of failure in products or services (or processes), including the possible failures that might be incurred during the Design, the Development, and the Production of a Product (or the Processing of a Service) or its components and sub-components (or its processes and sub-processes) - and addressed as well to evaluate the potential effects of such failure/s, and rank them in order of relevance - and providing a system for defining what actions (modifications, tests and controls, etc.) could and should be undertaken in order to eliminate or reduce the probability of such failure/s taking place....".

There is a Product FMEA, a Process FMEA and a Service FMEA.

PRODUCT FMEA is intended to analyse the Design Phase of a Product, with the purpose of identifying potential failures (of the Design Process itself and/or) of the Product being designed/engineered.

PROCESS FMEA is intended to analyse the Design/Planning Phase of an Industrial Process (which will produce the Product as final output), with the purpose of identifying potential failures (of the Design/Planning Process itself and/or) of the Manufacturing/Production Process.

SERVICE FMEA is intended to analyse the Design/Planning Phase of a new, proposed Service and its overall Process, with the purpose of identifying potential failures (of the Design Process itself and/or) of the Service and/or of the Process and sub-Processes having, as a final output, the Service under consideration.

The FMEA Technique can be well applied to the discovery of potential failures in any Process, including, for instance, Company Procedures, Company sub-Processes (support Processes), etc.

Besides, the FMEA Technique can be conveniently applied to identify potential failures in the "logistics" area (handling, internal transport, storage, installation, after-sales service, etc.).
 
 
In the case of Product FMEA (but not only) the key-word is Formalisation: of the (normally spontaneous) logical process adopted by Design Engineers to assure that all possible failures modes of the Product being designed (including its sub-assemblies and components) have been duly considered, together with their possible causes and effects/consequences.
The FMEA Techniques reduces the risks of the Product/Sub-Assemblies/Components failure because:
- it furnishes an aid to evaluate objectively the Design Characteristics and possible alternatives to the Design, with the purpose of avoiding Design modifications at a later stage
- it increases the probability to take into due consideration (all) potential failure modes at Design/Development stage, as well as their consequences on Product’s performance
- it supplies adequate output information and data necessary to prepare valid testing/commissioning plans for the concerned Product, apt to discover evidence of potential/real Product failure or accelerated/abnormal deterioration.

The FMEA Techniques reduces the risks of the Product/Sub-Assemblies/Components failure because:
- it outputs a comprehensive list of potential failure modes, adequately classified and ranked in order of importance, taking primarily into consideration the resulting impact on the Client (End User)
- as such, it furnishes a plan on the priorities of the supplementary actions/interventions to be undertaken
- it outputs a written document that opens the door to proposing corrective/preventive/improvement actions already at Design stage, and to monitor them over time
- it represents a reference basis for the examination of (possible) subsequent Customers’ complaints - for the analysis of future modifications/improvement to the Product - and for any further development of the Product and its Design.

WHO CONDUCTS FMEA AND WHEN
Traditionally, a Team is assigned to FMEA programs. Besides high level representatives of the Product Design/Development department, the Team should include also high level representatives from R&D, Production Development & Engineering, Production, Quality Assurance, Procurement, Plant Engineering, After-Sales Service, and, (not full-time) representatives from the Marketing and Sales Depts.
They meet regularly throughout the Design Phase (from inception to detailed engineering and release to production), and monitor the project throughout the Production Planning Phase, the Prototype Production Phase (if any), the initial testing, etc. up to the Product Launch, and over.
In the new-world enterprise, the FMEA Team is the product development team already described under Quality Function Deployment and Value Engineering.
Once again, the secret is a simultaneous, concurrent approach.

It is important to note that, under the FMEA angle of view, a failure is the total or partial Product non-compliance with the Design standards or specifications.
A Failure is such even if it is not perceived by the Client: because of its non-compliance to prescribed/designed standards.

The failure mode is the mode in which the Failure "might" take place, due to its potential causes (defects that "might" develop in the Product, or its Sub-Assemblies, or its Components).
The key-word is might: under the FMEA angle of view a Failure is "potential" as it is potential the Defect/s that might cause it.
A Failure and a Failure Mode investigated under a FMEA project "might" never happen and come to existence.
Failure Modes are found answering the simple question: "...what might happen (go wrong) in this Element?..."

Effects of a failure are "potential effects" (including any loss of performance) as seen from the end-user angle of view.
 
 
In the case of Product FMEA (generally called Design FMEA) the typical steps the product development team goes through are the following:

  • Design FMEA may be conducted at different complexity/detail levels, depending on focus: Product - Sub-Assembly - Part - Component - etc.
    The common practice is to start from the complete Product, and gradually proceed moving into lower levels, (and possibly) focusing only onto those Sub-Assemblies or Components that have proved to be "critical" during the higher level analysis.
    The starting point, therefore, is always to prepare a block diagram or tree diagram of the Product:
tree diagram
  • Then the FMEA drill is applied: for each Element under scrutiny all (main) functions are listed, briefly but clearly,
  • Using functions as a guideline, all possible Failure Modes are listed (for each function).
  • For each identified Failure Mode all potential Effects are then listed.
    The Effects of certain Failures might be very serious, or even catastrophic: they might endanger human life, they might constitute a hazard of any nature, or they might conflict with certain Standards (Pollution, Safety, Health and Hygiene, etc.).
    If this is the case, special remarks are made and recorded.
  • Then possible Causes for the listed Failure Modes are identified and listed.
  • Then for each identified Cause a relevant Risk Priority Index (RPI) is evaluated.
    To the purpose personalised Risk Severity Charts should be produced. Also the Probability that the concerned Failure might materialise is taken into due consideration.
  • At this stage the Team has a list of Causes of Failures (with associated Failures and Failure Mode descriptions), and all the relevant RP Indices.
  • Now Corrective Actions must be set. Corrective actions must be addressed to the Design or its Review method, in order to lower the critical RPIs by intervening on their parameters.
    (Note: in spite of being called Corrective Actions, they are actually Preventive Actions).

A similar method and drill is adopted in the Process FMEA and Service FMEA.


In all cases, the FMEA principle is to lower Failure areas with high RPI, irrespective of their RPI absolute value.


top
navigation through all synoptic pages published to date
(point your mouse over the number of a synoptic page to view its description)
01 02 03 04 05 06 06b 06c 07 07b 07c 08 09 10 11
12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
27 28 29 30 31 32 33 34 35 36 37 37b 37c 38 39
40 41 42 43 44 45 46 47 48 49 50 51 51b 51c 52
52b 52c 52d 52e 53 54 54b 54c 54d 55 56 56b 56c 56d 56e
58 59 60 61 62 63 64 65 66 67 68 69 70 71 71b
72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
87 88 89 90 91 92 93 94 95 96 97 98 99 100 101

 

 

 
http://www.scodanibbio.com
To fully exploit all features of this web site, please enable JavaScript and allow pop-up windows.