© ABSL Power Solutions 2007 © STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis TOTAL QUALITY MANAGEMENT F.M.E.A.

© STM Quality Limited STM Quality Limited What is an F.M.E.A.? Why do we need it? When do we do it? What do we do when it’s finished? Introduction

© STM Quality Limited STM Quality Limited What is a Failure Mode and Effect Analysis? F.M.E.A. is a simple way of predicting what might go wrong. By using a structured method, results can be quantified and hence compared.

© STM Quality Limited STM Quality Limited How Does It Work? Identifies critical and significant characteristics Helps engineers prioritise and focus on eliminating product and process concerns and help prevent problems from occurring.

© STM Quality Limited STM Quality Limited Purpose Utilise individuals’ knowledge and skills within a team environment Identify potential failures at the earliest possible stage of new design/process

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis F.M.E.A.s can be done for any design, manufacturing or in-service activity F.M.E.A.s are modular and can be carried out for single parts or large assemblies

© STM Quality Limited STM Quality Limited F.M.E.A. - Types Component Design FMEA Design FMEA System Sub-System Process FMEA Process FMEA Assembly Manufacturing System Component Sub-System System Component Sub-System

© STM Quality Limited STM Quality Limited Benefits – Design F.M.E. A. Aids in evaluating requirements and alternatives Aids in initial Design for Manufacture Increases probability of detecting failure modes and their effects Provides additional information for testing requirements Helps identify critical and significant characteristics Helps validate test methods

© STM Quality Limited STM Quality Limited Benefits – Process F.M.E. A. Identifies potential process related failure modes which will effect internal/external customers Reduces costs of repairs due to faulty process methodology Increases efficiency Establishes a priority system for considering corrective actions Identifies confirmed critical and significant characteristics

© STM Quality Limited STM Quality Limited F.M.E. A. and Control Plans F.M.E.AIdentifies Risks How Risks are Controlled Control Plan

© STM Quality Limited STM Quality Limited F.M.E.A. Model

© STM Quality Limited STM Quality Limited To meet Customer Requirements – A.P.Q.P. To keep up with competition To retain current business Help obtain new business Why Do A Failure Mode and Effect Analysis?

© STM Quality Limited STM Quality Limited Generating F.M.E.A.s Failure Mode and Effects Analysis Who initiates? Who prepares? Who updates? Who is FMEA customer? How is FMEA documented? When started and updated? When is FMEA complete? When to discard?

© STM Quality Limited STM Quality Limited FM.E.A.s are living documents and are updated when: Modification to a component, process or system is planned; Component is to be used in new environment; Customer concern arises. Managing F.M.E.A.s

© STM Quality Limited STM Quality Limited Process F.M.E.A.s

© STM Quality Limited STM Quality Limited Firstly, create a flow chart of operations Then identify boundary for analysis Next, create a flow chart for one operation Process Flow Chart

© STM Quality Limited STM Quality Limited Transport raw materials Process Flow Chart of Operations Op.10 PreparationOp.30 Weld Op.40 assemble Op.50 Trim to size Op.60 Inspect & Pack Store/Pack Op.20 Mould Boundary for analysis

© STM Quality Limited STM Quality Limited Place part on trim machine fixture Boundary For Analysis Press ‘Start’ button Op.50.1 Remove from fixture when cycle complete Op.50 Trim Op.50.2 Op.50.3

© STM Quality Limited STM Quality Limited Process/Function Requirements

© STM Quality Limited STM Quality Limited From Process flow: Enter a simple description of the process being analysed i.e. Place part on trim machine fixture; Indicate the purpose of the process being analysed i.e. Fully seat part in correct orientation; List separately other operations involved with that process; Process function contains both product and process characteristics. Process/Function Requirements

© STM Quality Limited STM Quality Limited What does the process do at this operation? What is the process purpose? What is its function? Define the Process Purpose

© STM Quality Limited STM Quality Limited Place part on trim machine fixture Process Purpose Press ‘Start’ button Op.50.1 Remove from fixture when cycle complete Op.50 Trim Op.50.2 Op.50.3 Locate part on fixture - correct orientation - fully seated Start trimming programme Position in checking fixture - fully seated Remove waste before packing

© STM Quality Limited STM Quality Limited Determine What Can Go Wrong

© STM Quality Limited STM Quality Limited Definition: Potential failure mode is the manner in which the process could potentially fail to meet the process requirements and/or design intent. It is a description of the non-conformance at that specific operation. Failure Mode

© STM Quality Limited STM Quality Limited Examine process flow using: No function Partial function Intermittent function Failure Mode

© STM Quality Limited STM Quality Limited Effects Of Failure Mode

© STM Quality Limited STM Quality Limited Definition: The effects of the failure mode on the customer. The customer could be the next operation, subsequent operations or the final customer / user. Effects of Failure Mode

© STM Quality Limited STM Quality Limited Identify potential effects on: next user downstream user ultimate customer vehicle operation operator safety Compliance with government regulations machines / equipment Effects of Failure Mode

© STM Quality Limited STM Quality Limited Effects of Failure Failure mode Next user Downstream users Ultimate customer Vehicle operation Operator safety Government regulations

© STM Quality Limited STM Quality Limited Effects of Failure Failure mode Next user Downstream users Ultimate customer Vehicle operation Operator safety Government regulations Failure mode: Incorrect Trim Programme Incorrect to checking fixture Packaged in wrong stillage Cannot fit to vehicle. Stop Production line Cannot fit to vehicle None

© STM Quality Limited STM Quality Limited Severity

© STM Quality Limited STM Quality Limited Definition: An assessment of the seriousness of the effect of the potential failure mode on the customer. Severity

© STM Quality Limited STM Quality Limited Hazardous without warning Suggested Severity Scoring EffectCriteria: Severity of EffectRanking 10 Hazardous with warning 9 LowMinor disruption to production line 100% of product may have to be reworked 5 NoneNo Effect1 May endanger machine or assembly operator…non compliance government regulation without warning

© STM Quality Limited STM Quality Limited Critical or Special Characteristic

© STM Quality Limited STM Quality Limited Identify Special Characteristics CRITICAL: Requirements that affect compliance with government regulations or safe vehicle / product function and require special controls (Score = 9 or 10) SIGNIFICANT: Product and/or test requirements important for customer satisfaction, summarized on Control Plan and require special controls (Score = 5 to 8,)

© STM Quality Limited STM Quality Limited Cause

© STM Quality Limited STM Quality Limited Definition: Potential cause of a failure is defined as how the failure could occur in terms of something that can be corrected or controlled. Cause

© STM Quality Limited STM Quality Limited Only specific errors or malfunctions (eg. Operator fails to remove waste) should be listed. Ambiguous phrases (e.g. Operator error, machine malfunction) should not be used. Cause

© STM Quality Limited STM Quality Limited Occurrence

© STM Quality Limited STM Quality Limited How frequently the cause is projected to occur. Based on: – Historical manufacturing/assembly failure rates with similar parts – Statistical data from similar process – Existing process controls – Customer concern data – Rejects, PPM, Warranty data Occurrence

© STM Quality Limited STM Quality Limited Very high Suggested Occurrence Scoring ProbabilityPossible Failure RatesRanking 10 Moderate6 RemoteLess than 1 in 500,0001 About 1 in 2 About 1 in 80 About 1 in 3 9 About 1 in About 1 in

© STM Quality Limited STM Quality Limited Controls

© STM Quality Limited STM Quality Limited Increasing inspection is only a temporary measure. Permanent Corrective Action is required. Emphasis must be placed on preventing defects rather than detecting them (e.g. S.P.C.) Controls

© STM Quality Limited STM Quality Limited In Process Control column on FMEA: Prevention Controls – Place a ‘P’ before each prevention control listed Detection Controls – Place a ‘D’ before each detection control listed Controls

© STM Quality Limited STM Quality Limited Prevention: (Preferred option) Prevent the cause / mechanism of failure or the failure mode occurring, or reduce their rate of occurrence Prevention Controls

© STM Quality Limited STM Quality Limited Detection: Detect the cause / mechanism of failure or the failure mode and lead to corrective actions Detection Controls

© STM Quality Limited STM Quality Limited Engineering specification tests Poka-yoke or error proofing Audible or visual warning devices In Process / Final inspection S.P.C. Process / Parameter audits Process Control Examples

© STM Quality Limited STM Quality Limited Detection

© STM Quality Limited STM Quality Limited Definition: Detection is an assessment of the probability that: The process controls listed will detect a potential cause /mechanism (process weakness), or The process controls listed will detect a subsequent failure mode. Detection

© STM Quality Limited STM Quality Limited Certain Suggested Detection Scoring DetectionLikelihood of DetectionRanking 10 Moderate4 Almost certainProcess control will almost certainly detect a potential cause 1 Process control will not and/or cannot detect a potential cause … or there is no process control Moderately high chance the process control will detect potential cause

© STM Quality Limited STM Quality Limited Severity Select and Manage Actions To ReduceConsider This ActionTo Accomplish Eliminate failure modes OccurrencePrevent cause(s), or reduce their rate of occurrence DetectionAdd to or improve the control methods Change the design... or the process if operator safety is involved Change the design or process Improve ability to detect a failure mode

© STM Quality Limited STM Quality Limited Risk Priority Number (R.P.N.)

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis We have seen that the F.M.E.A. asks three questions: s What might go wrong? s What effect would this have? s What caused the problem?

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis From the answers to the three questions we can work out a risk priority number: R isk P riority N umber

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis How do we calculate the R.P.N.? We simply use the scoring criteria easily remembered by: S everity of the problem O ccurrence of the problem D etection of the problem

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis Each is given a value from 1 to 10 Let’s try this out for S, O & D For Example, Severity = Occurrence = Detection = Each of these could be assessed in a rating from 1 to 10.

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis How can we use these values to give an overall risk? We multiply the three figures together: e.g. 7 x 4 x 3 = 84. So the R.P.N. is 84.

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis From the R.P.N. we can now see the areas of greatest concern i.e. Those failures with the highest risk priority numbers

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis We can now focus our attention on the worst problems – those with the highest R.P.N. With limited resources, this must be a good idea We can now eliminate or reduce the potential failure

© STM Quality Limited STM Quality Limited Recommended Actions

© STM Quality Limited STM Quality Limited Recommended Actions The intent of any Recommended Action is to reduce rankings in the following order: Severity Occurrence Detection

© STM Quality Limited STM Quality Limited Responsibility & Target Date

© STM Quality Limited STM Quality Limited Responsibility Each action must be assigned to a specific individual and not a dept. / organisation If the individual is not in the team a team member should be assigned responsibility for communication and feedback of action with a target date.

© STM Quality Limited STM Quality Limited Actions Taken

© STM Quality Limited STM Quality Limited Actions Taken After the corrective action has been identified, estimate and record the resulting severity, occurrence and detection rankings Calculate and record the resulting R.P.N. P.F.M.E.A. team must review the revised R.P.N.s to determine if further action is necessary. If no action write ‘None’.

© STM Quality Limited STM Quality Limited Actions Taken Once the actions have been implemented, the estimated values, ‘the future’, becomes ‘the present’ and can be incorporated into the LHS of the form on the next F.M.E.A.

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis Advantages of F.M.E.A.s s Customer confidence s Improved quality & efficiency s Improved participation across traditional boundaries

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis More advantages of F.M.E.A.s s Uses extensive & untapped personnel/process knowledge to improve new & existing work s Provides a vehicle for continuous improvement s Supports product liability

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis There are drawbacks for F.M.E.A.s: s Must be adequate time & resources for F.M.E.A.s s Product Liability s Need for in-depth product & process or design knowledge

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis Remember - F.M.E.A. is a practical activity and there will be differing interpretations regarding to the failure modes and rankings - this does not matter, provided that the team does not get bogged down in this way!

© STM Quality Limited STM Quality Limited Failure Mode and Effect Analysis Keep the meetings short and the tempo sharp! Design F.M.E.A. team - Chairman, Production, Service, Quality Personnel Process F.M.E.A. team - YOU CHOOSE!