DFMEA (Process Failure Modes and Effects Analysis)

Design Failure Mode and Effect Analysis (DFMEA) is a Six Sigma tool that is used to identify potential failure in products, systems, or processes as well as the cause for these failures and their outcomes. It is an effective way to attempt to avoid failures and enhance the overall process of production within a facility. Although DFMEA was first developed for rocket science, a wide variety of industries can use this tool to reduce the occurrence of failures. 

Defects in products can cause harm to any business. Whether failures lead to product recalls or have a catastrophic impact on consumers (as is the potential in the rocket industry), design flaws can set a company back significantly. Using an analysis methodology can detect issues much more easily and quickly. By conducting tools such as DFMEA, businesses can solve problems before they make a negative impact.

DFMEA is used during the design and redesign phase of a project. Risks will be assessed either with a completely new design, with the modification to an existing design, or when a change in environment/duty is introduced to the current design. As a qualitative tool, you’ll consider what can go wrong with the product, why it could go wrong, how likely it will go wrong, and what the consequences may be. 

Using DFMEA to identify failure involves a five step process:

  1. Define the failure modes and severity. Failure modes include full, partial, inconsistent, degraded, and unintended. The severity is ranked from 1-10, with a 2 regarded as a minor annoyance and a 9 regarded as something that has dangerous/catastrophic implications and is likely to violate regulations.
  2. Define the causes of failure. This factor varies, however common causes of failure include inferior construction materials or a mistake in calculations. Once the exact cause is identified, you may then determine the occurrence ranking of how likely the failure is going to happen on a scale from 1 (known to be isolated) to 10 (the product or design is new and estimating occurrence is theoretical).
  3. Inspect the current design controls. These tests verify design safety. This step is also where detection is ranked on a 1-10 scale. The design of a product may have safeguards to prevent the failure (1), or it may be impossible to detect a failure before it occurs (10).
  4. Determine the Risk Priority Number. The RPN is calculated by multiplying the scores you have given for severity, occurrence, and detection. Failures that are high severity and frequently occur are given the biggest priority. Once the RPN is determined, you can take actions such as eliminating failure modes of high severity, attempting to lower the occurrence of failure, or attempting to improve the detection of failure.
  5. Repeat until the RPN reaches the desired threshold. Repeatedly follow these steps until the Design Failure Mode and Effect Analysis has resulted in less failures, or no failures at all, in design. 

When used correctly, DFMEA can boost productivity and profits, protect customers, and eliminate waste.

 
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