To avoid confusion, I will begin with a clarification. The full name of the document to which we refer generally as a FMEA (“fee-mah”) is Potential Failure Modes and Effects Analysis. This is not the ‘P’ to which I refer, however.
The title, “P” is for “Process,” is intended, first, to differentiate between a PFMEA (Process FMEA) and a DFMEA (Design FMEA). This differentiation refers specifically to product design and manufacture, as the distinction between them blurs when discussing service delivery systems.
Second, and the focal point of this post, is to differentiate between process and product. Many manufacturing organizations develop product FMEAs, mistakenly identifying them as process FMEAs.
A design FMEA analyzes the potential failures of a product’s design elements – materials, geometry, load stresses, etc. Any feature or specification that could lead to physical failure, product malfunction, personal injury, or property damage must be thoroughly reviewed and the associated risks mitigated. Features that encourage improper use, resulting in injury, damage, premature failure, or reduced performance also require scrutiny.
A process FMEA analyzes the potential failures of a single manufacturing process. Process failures can range from an aesthetic imperfection to interruption of a downstream process to premature failure in service by the end user. The broad range of potential consequences, from minor dissatisfaction or inconvenience to serious injury or extensive property damage, dictates that a careful and thorough analysis be performed on each process utilized to manufacture and deliver a product.
A product FMEA is a compilation of process and design information. It depicts the sequential progression of a product through each process required for its manufacture. If the design and process FMEAs are in place, a product FMEA may not be necessary. It can, however, be useful as an overview to aid in technology reviews, capacity planning, or program and portfolio management. When used for this purpose, the document consists primarily of references to separate FMEA documents. Information unique to a product can be added, but is an uncommon requirement. Due to the overlap of the information presented in each, the product FMEA and Process Flow Diagram (PFD) may be created as a single document.
While the product FMEA can be helpful when used appropriately, it is important not to confuse it with a process FMEA. The risks of doing so include:
The ideal output of a FMEA development effort is not a FMEA, a single document that attempts to be comprehensive. Instead, a FMEA package should be created that includes a design FMEA, a number of process FMEAs, and a product FMEA or PFD. Some process FMEAs may already exist, as well as some elements of the design FMEA. If so, review and update them before including them in the package.
The responsibilities within a manufacturing facility with which a well-crafted FMEA package can assist include:
If your organization is not being well-served by FMEAs because they are insufficient, or simply do not exist, feel free to contact me for guidance. Once your FMEA-development infrastructure is in place, it will add value to your operations for the life of your business.
Jody W. Phelps, MSc, PMP®, MBA
JayWink Solutions, LLC
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