Sunday 18 April 2021

Quality One Australia


Quality One Blog

Robustness and FMEA Effects of Failure
2/02/2021 12:00:00 AM
By David Kelly
Robustness is a key fundamental element in APQP and FMEA product and service campaigns. It is the ability of the engineering or development team to have traceable product and service characteristics move through the product and service development cycle to ensure the customer receives the product or service as they desire. Customers would include end consumers and industry or government regulatory bodies. Customers can also include internal downstream processes in the development cycle - at a minimum they would receive the characteristics requirements of the product or service from earlier sections or phases in the product development process.

Robustness occurs both vertically and horizontally in the product and service development cycle. Vertically within the product, subsystem, component structure through the cause failure mode relationship in the DFMEA and PFMEA (the cause of failure at the system level becomes the failure mode at the subsystem level) and horizontally as the different phases development are entered. Noise factors in a Parameter Diagram as causes of failure in the DFMEA for example.

Cause of Failure at one level is the failure mode at the level below.




Noises identified in the P-Diagram become Causes in the DFMEA

The focus of this article will be on the robustness of the effects column in the DFMEA and PFMEA. There are several areas of focus for robustness in the product and service development process in particular the transition from DFMEA to PFMEA amongst others. We will save those for future articles. The effects column in the 4th Edition FMEA is developed with the Function, Failure Mode, Effects and Severity section in the FMEA and in the new AIAG/VDA Handbook is in the Failure Analysis (Step 4) section.

Sound robustness is one of the forerunners to developing and moving toward integrated Industry4.0 and Quality4.0 organisations. Connectivity, availability and transparency of information, intelligent processing and interaction of data along with the digitisation and integration of vertical and horizontal value chains are intrinsically linked to the robustness level and organisation can produce in its product and service development models and processes. A highly robust product and service development process connects and integrates all its tools (QFD/VOC, DFMEA, DVP&R, Characteristics Matrix, PFMEA, DFA/DFM, MSA, PCP and SPC) allowing them to interact and transparently follow characteristics, in particular critical and significant characteristics through the process.

Robustness is the basic building block into EIMS (Enterprise Integrated Management Systems) and the data in the effects of the FMEA is one small block in many that delivers ORA (Organisational Robustness Analysis). The product and service development process (APQP) is an organisational process within EIMS that requires prominent levels in an ORA. This is measured by the levels of connectivity, interaction, transparency and intelligent processing which requires standards of retrieval for the data to give maximum use to the organisation. The effects column in both the DFMEA and PFMEA are one small part in this.

In some cases in the development of DFMEA and PFMEA it has been witnessed that organisations are using the generic FMEA severity criteria as descriptors for the effect. For example in the case of an engine losing power the descriptor may read Loss of System Function with no mention of what is happening to the system, neighbouring assemblies or the end customer. While this offers certain efficiencies within the DFMEA and PFMEA in terms of time and rating the severity it is done at the expense of robustness in the product and service development system.

Poor use of DFMEA Effects column that could lead to misallocation of severity and loss of field data robustness

With no descriptor on the effect of failure
  • neighbouring systems are potentially denied vital information on potential input failure or variance and hence the true level of the severity of failure may not be recorded as it may escalate to a higher rating.
  • escalation to higher system events may not be determined potentially missing vital design actions and misallocating the severity level.
    • With a misallocated severity level in the DFMEA the severity level in the PFMEA may also be misallocated leading to insufficient process controls on a critical characteristic in the design
  • multiple effects of failure that may exist for a particular failure mode are missed.
    • While facilitators strive for the highest effect of failure and may not necessarily look for other effects once a high value is found there is value in capturing all effects which becomes relevant in the next point. Lower scoring effects can be determined and captured outside the FMEA sessions which should focus on driving toward action.
  • field feedback/failures root cause analysis will be missing a vital robustness link that potentially reduces or eliminates the need for lengthy root cause analysis.
    • Field failures and feedback will be delivered to the organisation in a manner that is the effect on the end customer/consumer and at times in an emotive manner. With only the severity ratings as an effects descriptor the effect described by the customer will not be able to matched in a database search, file search or any search for that matter. The robustness link has been lost. The simple view of then being to match the effect with a failure mode and then a potential cause cannot be obtained and the organisation is left with the full requirement of root cause analysis and no avenue to circumvent any potential investigation based on what the organisation already knows from its FMEA activity.

Robust use of the effects column in FMEA leads to better identification of severity, capturing multiple effects of failure and allowing more descriptive searches for field problems that can identify potential root causes in a more efficient manner.


Placing the actual effect on the product and the end customer/consumer in the effects column of the DFMEA and PFMEA if not current practice in an organisation is a starting point to delivering robustness in the product and service development system and will lead the organisation towards the type of holistic thinking and action required to be at Industry4.0 and Quality4.0 levels.


Other Blog Posts

WinSPC How to Series

Posted 21/03/2021
Quality One Australia introduces the first of the WinSPC How to Series videos.

Quality One - Discover the Value

Quality One Australia was first established as Quality Associates Australia in 2005 due to an overwhelming response for its partner company, Q1 - Quality One USA to provide quality training, consultation and facilitation services to various industries throughout the South East Asia region.  We rebranded in 2018 to more closely align with our US partner.

We specialise in end to end process and quality management from initial education, training, curriculum and certification ( Lean Six Sigma , 8D , FMEA, APQP, SPC etc. ) through to the implementation of quality management, electronic management and business and process improvements across your organisation. We deliver change, improvement and solutions to organisations locally, throughout Australia, across the Asia region and globally through our Q1 network.

If you desire this level of excellence then let us help you achieve your goals.
Learn More
Copyright © 2021      This website and its associated software are the property of Quality One Australia. This software may not be copied redistributed or modified for any purpose without the express written permission of the copyright owners. All rights reserved.