Depending upon the complexity of product design and its application, the DFMEA exercise can quickly become a tedious exercise if not done through a structured format. In this article, we outline five key tactics that can streamline DFMEA analysis.
By Bryan Christiansen | Limble CMMS
Design Failure Mode Effect Analysis (DFMEA) is a well-known engineering technique used to improve the effectiveness of a product’s design. Unlike FMEA which has a broader application to products, processes, or services, DFMEA focuses on the failure modes addressable during the design phase of a given product. However, the underlying objective of the analysis is still the same as FMEA — to analyze failure modes and develop controls to mitigate the risk of design failure.
One: Define the boundary of DFME analysis
Setting the boundary of analysis requires keen understanding of the product under consideration and its intended function. Oftentimes, machine designs and other equipment in industrial settings must interface with various other equipment in a complex logical relationship. The occurrence of failure in one piece of equipment can induce failure in another … or in other systems at a higher level in the installation hierarchy.
For example, failure in a bearing can cause overheating in the induction motor which can in turn cause the motor to draw excessive current. Sustained overcurrent may in turn spur excessive heat in the motor windings — ultimately spurring an arc-flash condition and irreparable physical damage to the motor.
One of the easiest ways to understand DFMEA boundaries is to review the hierarchy of the machine design along with its subsystems and components. Because DFMEA is a bottom-up logical approach that starts from the lowest design level, a component-level hierarchy helps analysts most accurately and consistently model the design’s boundary.
Two: Get quality historical data for the DFMEA
Because DFMEA involves analysis of design failure modes, it’s quite helpful to have on hand any and all historical information about the limitations and modes of failure of previous design builds and legacy equipment installed onsite.
Often DFMEA analysts have a hard time collecting the right and sufficient information about the failure modes. Should an engineering team’s redesign focus on improving the motor stator, rotor, housing, fans, or something else? To help answer this question, DFMEA analysts must clearly identify the most problematic failure modes and why they happen … especially as installation mistakes and misuse on the part of the end user aren’t generally correctable through product design changes.
Consequently, the lack of data leads to confirmation biases about the product and the analysis eventually shifts away from a core data-driven approach into more qualitative brainstorming sessions.
Three: Understand a design’s operational context
Accurate DFMEA depends on careful review of the operating conditions within which a design is going to operate. This is because a given piece of equipment subjected to the same failure mode may perform differently when installed in two different environments.
For example, the failure mode of a motor in a semiconductor-manufacturing workcell might necessitate a different response than that same motor failure in a small-scale craft-beer bottling machine. The former typically requires quick response to save expensive workpieces; the latter might only need to alert an operator to attend to the machine when next available — or send machine diagnostics to a technician.
Four: Build design-team DFMEA competencies
It takes a diverse team of professionals to undertake a DFMEA. This is because no single person possesses the education and experience to review every single kind of failure mode that is possible for a given machine design.
The recommended approach is to setup a team that knows the product characteristics as well as the design’s intricate workings and operating conditions under which the automated equipment will operate. Ideally, this team should have skills in design, manufacturing, operations, reliability, human factors, and product safety.
Five: Leverage computerized maintenance management systems (CMMS)
One effective way to improve DFMEA is to ensure failure modes identified during the design phase — and the operational, maintenance, and disposal phases — are recorded and maintained.
Enabling this closed-loop approach is deployment of a CMMS system with the capability to record and sustain a wide range of product data related to failures, maintainability, reliability, and resource data. Here, the purpose is to relay the information back to the design engineers so that future machine designs can improve through well-informed decision-making.
About the author: Bryan Christiansen is the founder and CEO of Limble CMMS. Limble is a modern easy-to-use mobile CMMS software that takes the stress and chaos out of maintenance by helping managers organize, automate, and streamline their maintenance operations.
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