Effective preventive maintenance begins with design. Flaws in the design of products, equipment, or systems can lead to ongoing maintenance issues, unforeseen process failures, and diminished customer satisfaction. This is why Design Failure Mode and Effects Analysis (DFMEA) is so important. DFMEA refers to the systematic analysis of failure modes beginning at the design stage.
DFMEA identifies design issues that might lead products, equipment, or systems to fail, and is meant to provide insights on how to address these issues before initiating the production process. Taking these steps during the product development process can ultimately improve the reliability of your production process and the quality of your output. Together, these outcomes can have the impact of reducing the burden of labor on your maintenance team, lowering the cost of maintenance activities, and offsetting the potential risks that come with unplanned downtime.
Organizations that incorporate DFMEA into the development of products, equipment, or systems are in a better position to identify potential causes of failure before they can manifest in the production process. As the discussion below will demonstrate, this approach translates into a more optimal production process, better products, and more efficient maintenance programs.
What is DFMEA?
Design Failure Mode and Effects Analysis (DFMEA) is one dimension of the broader Failure Mode and Effects Analysis (FMEA) process. This dimension is focused on the design phase of product development. The goal of DFMEA is to identify and mitigate issues in advance of the process and manufacturing phases of production.
Effective DFMEA improves product quality control by first identifying potential design weaknesses, and subsequently considering the possible impact of these weaknesses on both operation and design. Organizations ultimately take steps to mitigate these design flaws before they can lead to process and production failures.
The purpose of DFMEA
DFMEA serves several key purposes in the production process including:
- Identifying all possible failure modes for each component of product design
- Assessing the risk associated with each potential failure mode with consideration of the potential severity, likelihood of occurrence, and detectability of each risk
- Implementing design changes to prevent or reduce the likelihood of failures
- Documenting the design analysis process to facilitate audit preparation, regulatory compliance, and continuous improvement; and
- Improving failure detection controls as well as strengthening failure prevention controls.
Professionals responsible for DFMEA
DFMEA is an inherently collaborative process, one that is typically conducted by a cross-functional team with a diverse set of skills, experience, and expertise. The following are among the key professionals who will typically participate in this process:
- Project managers are responsible for coordinating all aspects of the DFMEA process including involving all relevant stakeholders.
- Design engineers contribute their knowledge to the technical aspects of the product design.
- Reliability engineers measure the probability and impact of potential failure modes.
- Maintenance technicians provide insight on how preventive and corrective actions will be performed.
- Supply chain and procurement specialists oversee inventory, tracking, and availability of the tools, parts, and materials required to ensure design quality.
Why is DFMEA important?
DFMEA is an important part of the production process because it anticipates and resolves design issues before they can manifest as costly, time-consuming, and disruptive production failures.
Below, we take a closer look at some of the fundamental benefits of implementing DFMEA.
- Improved product quality and reliability, with potential failure modes being addressed and mitigated at the earliest stages of the production process
- Cost savings, with the prevention of design failures reducing the costs that come with repairs, recalls, and warranty claims
- Risk mitigation, with the structured approach to design resolution helping to prevent production issues before they can grow into safety and operational risks
- Regulatory compliance, particularly in the application of risk analysis, quality assurance, and documentation
- Continuous Improvement, with an iterative approach to analysis, ultimately making it possible to learn from past experiences and enhance future designs
DFMEA and FMEA
Design Failure Mode Effects Analysis (DFMEA) and Failure Mode Effects Analysis (FMEA) are two closely related but distinct concepts. The primary difference is their scope. DFMEA is one type of Failure Mode Effects Analysis (FMEA). FMEA is an umbrella term that encompasses Design FMEA as well as System FMEA and Process FMEA (PFMEA). Each of these analytical methods focuses on a different phase in the production process.
FMEA
Failure Mode Effects Analysis (FMEA) is a multi-stage process. Each of the analytical modes included under the FMEA umbrella is critical to a different stage of the product lifecycle, with System FMEA ensuring the functionality, reliability, and interconnectivity of the overall system; DFMEA ensuring optimal product design; and PFMEA minimizing the risk of failures in the manufacturing process.
System FMEA
Whereas DFMEA is focused on the risk of failure in the design process, System FMEA is concerned with the potential for systemwide failure and how this might impact product development. System FMEA examines interactions between components in a connected system (i.e. equipment, technology platforms, subsystems) to identify and prevent system-level failures. This mode of analysis is particularly valuable at the early stages of product development and can help illuminate systemic issues that might diminish the quality of end products.
Process FMEA (PFMEA)
Process Failure Mode Effects Analysis (PFMEA) is a method used to analyze the potential for failure during the manufacturing phase of production. In addition to anticipating possible areas of failure in the production process, PFMEA also provides an understanding of the likely impact of failure on your overall operation as well as strategies for mitigating this impact.
What is the DFMEA process?
The DFMEA process provides a framework for the systematic evaluation of potential design failures before they can occur. This naturally means that the phase must begin early in the product development process. Below, we outline the steps required to implement this important and proactive failure mitigation strategy.
Preparation
- Define the scope of your analysis including your objectives and the system, product, or component to be analyzed.
- Assemble a cross-functional team that includes a managing coordinator, design and reliability engineers, maintenance personnel, and others with a stake in quality control.
- Gather relevant information including design documents, product specifications, and historical data.
Structural and functional analysis
- Deconstruct relevant products or systems to understand individual components, their key functionalities, and the basic performance requirements for achieving each of these functions.
- Create a visual representation such as a block diagram to represent the relationships between components and subsystems.
- Identify and list all potential failure modes for each function of each component and subsystem.
Effects and cause analysis
- Determine the consequences of each potential failure mode on the overall product, system performance, and user experience.
- Identify the operational areas likely to be impacted by these effects such as productivity, efficiency, safety, and/or compliance.
- List the potential root cause for each potential failure mode.
Severity, occurrence, and detection ranking
- Calculate a severity ranking for each failure mode using a scale of 1 to 10, with 10 indicating the most severe impact on operations, and 1 indicating the least severe impact.
- Calculate an occurrence ranking for each failure mode using a scale of 1 to 10, with 10 indicating the greatest probability of failure and 1 indicating the lowest probability.
- Calculate a detection ranking for each failure mode using a scale of 1 to 10, with 10 indicating the least likely to be detected before failure, and 1 indicating the most likely to be detected.
Risk Priority Number (RPN) calculation
- Calculate the RPN for each failure mode by multiplying Severity by Occurrence by Detection (i.e. Severity × Occurrence × Detection=RPN).
- Rank failure modes based on their RPN scores, with higher values indicating high-risk events.
- Perform criticality analysis of the highest priority failure modes, considering features such as safeguards and redundancies.
Implementation and Documentation
- Develop an action plan for each high-priority failure mode and assign team members to implement the recommended actions.
- Monitor and evaluate the effectiveness of implemented action plans.
- Keep thorough records of the DFMEA process and use these as reference points when conducting periodic and ongoing updates and reviews.
The role of CMMS platforms
Computerized Maintenance Management Systems (CMMS) can be invaluable for both streamlining and improving the impact of your design analysis. The digital tools and sophisticated features provided by the leading-edge CMMS platforms can facilitate collaboration, inform analysis, and delegate the assignment of duties required to carry out the DFMEA process.
Below, we take a closer look at some of the key benefits of CMMS-driven DFMEA, particularly as this approach compares to manual implementation.
- Centralized data storage, allowing collaborative access to design documents, easy retrieval of analytical data, and unfettered sharing of risk assessments
- Heightened automation, including automatic calculation of metrics such as RPNs
- Enhanced tracking for DFMEA activities and automated reporting on outcomes and improvements
- Improved documentation from initial analysis to final implementation of corrective actions, providing a valuable audit trail and improving compliance with regulatory requirements and industry standards.
- Seamless integration with other systems such as Enterprise Resource Planning (ERP) and Product Lifecycle Management (PLM) systems, ensuring data is aligned across business processes and systems
The result of these benefits is a DFMEA strategy that is markedly more efficient, accurate, and consistent than manual methods of design failure mode analysis.
Auditing your DFMEA process
Continuous improvement is a critical element of an effective DFMEA program. To get the best results out of your DFMEA, you need to be sure that the process itself is being implemented optimally. This requires regular and comprehensive auditing.
Below, we outline the key steps in the auditing process.
- Define your objectives, such as ensuring regulatory compliance, measuring the effectiveness of risk mitigation, or verifying the accuracy of your criticality assessment.
- Assemble a team with the appropriate expertise, including members from quality, design, manufacturing, and reliability engineering.
- Prepare an audit checklist based on relevant regulations, industry standards, and internal requirements.
- Conduct your audit including a review of all DFMEA documentation, evaluation of risk prioritization calculations, and assessment of corrective actions as well as their efficacy.
- Report your findings, documenting discrepancies, identifying weaknesses in the process, and spotlighting areas for improvement.
As you evaluate the effectiveness of your DFMEA process, you’ll want to be wary of certain commonplace mistakes. Some of the typical pitfalls of DFMEA implementation include a lack of clear objectives, the absence of a truly collaborative framework, and a misplaced focus on process over results.
The best way to steer clear of these pitfalls is to partner with an experienced team of consultants. Before auditing your DFMEA process, schedule a call with one of Limble’s experts and find out how you can ensure the best possible outcome.
