FMEA - Plan and implement improvement actions and establish revised RPN
We are now nearing the completion of the DFMEA process whereby the identified and agreed actions are to be planned and implemented. To this end, as well as throughout the FMEA process in general, we use the Deming P.D.C.A. Cycle.
Introduction
In this final FMEA article I will discuss the process of planning and implementing the actions necessary to reduce RPN numbers in the order of: -
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Reduce the severity of the effect of failure – this is the most difficult to do as it will normally involve designing out the function. If this cannot be done: -
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Reduce the likely occurrence – this is the most cost effective in most cases and certainly so when compared with the above option
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Improve detection methods – this can be costly, particularly if involving detection rather than prevention
As already mentioned the planning and implementation is best served by using the Deming Plan-Do-Check-Act cycle. It is applied as follows: -
PLAN – plan the implementation of the corrective or improvement action. These may have wide ranging impacts across the design and design verification processes. All actions should be comprehensively considered in terms of the likelihood of success. This means that testing modifications may need to be modelled during the planning stage. Establish how success will be measured or assessed.
DO – Carry out the modifications as planned to the design, design processes or test processes. This includes documenting the changes in all associated processes and reviewing test data outcome requirements. It is important to ensure that the changes are made permanent to ensure “old or established” methods are not readopted (Ensure procedural documentation is updated and re-issued. Make the change sustainable).
CHECK – Carry out checks to ensure that the changes have taken place and are effective. This may not be feasible using practical methods, so modelling may be required, which should have been planned for as above. Have the changes had the planned effects, has the previous Severity, Occurrence or Detection levels been improved as planned?
ACT – Ensure that all data has been recorded, review the DFMEA and update the Severity, Occurrence and Detection ratings accordingly. This should result in a required reduction in the RPN. If outcomes are not as planned, take further actions to achieve the required improvements.
What Next?
What we have been through with these series of articles is just the beginning. FMEA fits within the processes of new product introduction and release and has direct linkages with other design tools including: -
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Product reliability
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Piece part approval
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Design verification process
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Adjoining FMEA efforts
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Problem Solving
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Robustness engineering
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To name but a few………………………..
The message therefore is quite clear - FMEA is only successful when and if it is an integrated part of the business and quality processes. Failure to do so makes FMEA a “bolt-on” activity. This less effective.
Assessing Questions
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Have all recommended actions been completed?
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Have all required process and system documentation been completed in accordance with company standards?
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Have any shortfalls in terms of expected outcomes been addressed through further considered action planning?
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Have all outstanding questions been closed, new ones added and the question log updated?
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Has the FMEA record been updated and communicated to all interested parties?
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Have all the team members been thanked for their contribution?
Next Time
Next time you are tasked with carrying out an FMEA, I hope you will feel better equipped. Remember to download the FMEA Snap-Shot and use this as a reminder of the steps that need to be taken to get the best from your FMEA efforts.
Finally, thanks for sticking with me through these articles. I hope they have helped. If you need any further assistance, please visit www.resustsresults.co.uk/fmea.
Graham Cripps
Results Consotium Ltd
