Modified DD2977: A Simple Alternative to Process Failure Mode Effect Analysis

Why Should You Attend:

The new (2019) AIAG/VDA FMEA manual (2019) for product realization processes offers, per my opinion, the best available process for identification, assessment, and mitigation of risks associated with product design and product realization processes. The use of process FMEA is required by IATF 16949:2016 clause 8.3.5.2.

There is on the other hand something to be said for Robert A. Heinlein's statement in Starship Troopers (1959) to the effect that, if you equip somebody with an overly-complicated weapon system (or tool), "…somebody a lot more simply equipped—say with a stone ax—will sneak up and bash his head in while he is trying to read a vernier.” A stone ax that will do the job, and which people will actually use, is more effective than a vernier that goes unused (or is not used effectively) because of its relative complexity.

The Army's DD2977, Deliberate Risk Assessment, is very similar in concept to PFMEA, and compatible with PFMEA. It is also much simpler; the original instructions fit on a single page. It is in the public domain as a publication of the U.S. Government, and it was designed by military professionals who deal with risk for a living. DD2977 therefore gives organizations a simple and user-friendly alternative to PFMEA that is likely to deliver usable results for its processes.

A complete process FMEA can have 20 or more columns, in addition to the header that provides information about the process and associated responsibilities. The Army's public domain DD2977, Deliberate Risk Assessment worksheet, has six columns plus a field for a supervision plan and a recommended course of action. Even if we add some additional columns to take advantage of the newest FMEA approach (per the AIAG/VDA 2019 manual), it is still far simpler. The instructions for DD2977 as written, meanwhile, fit on a single page as opposed to requiring an entire manual.

DD2977 is nonetheless synergistic with traditional PFMEA. Both processes examine the structure of a process and the functions of its process steps, along with potential failure modes and their effects. PFMEA assesses risks according to Severity, Occurrence, and Detection, and summarizes the result with a risk priority number (RPN) or the superior action priority rating from the new AIAG/VDA manual. Both processes also call for identification of controls that prevent or detect a failure, and cite the superiority of engineering or machine-based controls over administrative or behavioral controls.

DD2977 also uses a Severity rating system that can be easily cross-referenced with the one from FMEA, but combines Occurrence and Detection into a probability or "expected frequency" rating. DD2977 users therefore need to assess only how frequently a failure will happen (Occurrence) and escape (Detection) to cause trouble. DD2977's risk assessment matrix also overcomes a well-known problem with the risk priority number; the latter is the product of three ordinal numbers and does not always reflect the true relative risk of a failure mode [1]. Both approaches, DD2977 and FMEA, then call for the implementation or improvement of controls that eliminate or reduce the risks in question.

Areas Covered in the Webinar:

1. Scope and purpose of modified DD 2977; product realization processes, administrative processes, and service processes for which a simpler approach is suitable and for which the customer does not require formal PFMEA
2. Key definitions (commonality between DD 2977 and PFMEA)
• Controls
• Failure mode, failure cause (formerly mechanism), and failure effect
• Occurrence and Detection (PFMEA) and Probability (DD 2977)
• Severity (both systems)
• Risk Level (DD 2977) and Action Priority (PFMEA)
3. Procedure for Modified DD 2977 (enhanced with PFMEA methodology)
• Structure and Function Analysis; what are the process steps, and what are their deliverables?
• Failure and Risk Analysis; how can the process steps fail to achieve their objectives? What controls, if any, remove or mitigate these risks? What is the resulting initial risk level?
• Optimization; how can the failure effect be removed, or the failure causes disabled? What new or improved controls can be installed for this purpose? What is the resulting residual risk level?
• Documentation (organizational knowledge), and share lessons learned with related processes.
4. Risk Assessment Review. PFMEA is not a once-and-done activity; it must be reassessed in response to changes in the process (management of change issue). The same applies to the modified DD 2977. Whenever anything is new or changed, it introduces the risk of unforeseen consequences to the process.

Who Will Benefit:

• Quality managers, engineers, and technicians, and others with responsibility for advanced quality planning (AQP) or PPAP from all manufacturing and service companies.

William Levinson
Principal Consultant, Levinson Productivity Systems

William A. Levinson, P.E., is the principal of Levinson Productivity Systems, P.C. He is an ASQ Fellow, Certified Quality Engineer, Quality Auditor, Quality Manager, Reliability Engineer, and Six Sigma Black Belt. He is also the author of several books on quality, productivity, and management.

Topic Background:

Process failure mode effects analysis (PFMEA) plays a central role in advanced quality planning (AQP). Many organizations seem reluctant, however, to develop formal PFMEA's because it is a relatively extensive activity. PFMEA's focus on physical controls such as error proofing and self-check systems is meanwhile most suitable for processes that make physical products. While PFMEA also works for services, this is not the principal and original focus of its application. A modified version of the Army's DD2977, Deliberate Risk Assessment worksheet, is much easier to use and is likely to be sufficient for relatively simple product realization processes, administrative processes of a quality management system, and services.

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