What is Design Failure Mode and Effect Analysis – DFMEA

The method of design failure mode and effect analysis, or DFMEA, aids engineers in comprehending the possible risks connected to a design. One best practice that addresses issues such as these is the introduction of FMEA during the design process.

What could go wrong in terms of design . Design engineers employ a process called Design Failure Mode and Effects Analysis (DFMEA) to make sure that products fulfill user needs and function as planned. DFMEA assesses the entire architecture of product systems and parts in order to identify probable failure modes and reasons. Alternatively referred to as Design FMEA, it outlines suggested courses of action to remove or reduce potential effects of design failure on clients. Particularly helpful in the industrial sector, where risk mitigation and failure avoidance are essential, is Design Failure Mode and Effects Analysis. Teams may enhance the safety of their designs, gain a better understanding of them, and produce high-quality products by carrying out an efficient DFMEA.

What is the Difference Between DFMEA and FMEA

The main difference between DFMEA and FMEA is that DFMEA specifically focuses on identifying failure modes, causes, and effects of a product design, while FMEA provides general guidelines which can be applied to a process, service, and more. Design Failure Mode and Effects Analysis is also often related to Process Failure Mode and Effects Analysis (PFMEA), but they differ in which phase of the product development process each of them is conducted.

Why is DFMEA Important

DFMEA saves the time and money on product development by assisting engineers in identifying and resolving possible design flaws early on. A more robust designs with well-defined requirements can also be produced by using the DFMEA approach. For instance, a component shouldn’t be included in the design if it serves no use.

Who Should be Involved in DFMEA

Before releasing the designs to the manufacturing and process engineering departments, the initial Design Failure Mode and Effects Analysis should be finished. This gives enough time to evaluate the design before examining the manufacturing process. If the current design is going to be altered for the purpose of improving the product or as a result of a previous failure, then DFMEA should also be performed.

How to Perform DFMEA Process in 10 Steps

The procedures for implementing DFMEA often vary among industries, including automotive, nautical, and aerospace, and are dependent on specific corporate norms. Although the procedure initially seems daunting, it actually makes sense as a methodical and ordered approach to analysis. Teams can explore this example of a 10-step DFMEA procedure to get started:

Step-1: List each system with its function and other design requirements

Dividing the product design into systems and components, each with a distinct function, and arranging them in a design and function tree is one of the simplest ways to achieve this. These illustrations aid in illustrating how the systems, component functions, and overall design relate to one another. For instance, the seat itself (to support the user’s weight), aprons (to reinforce the seat’s edges), corner blocks (to link aprons to the legs), and fasteners (to hold the corner blocks to aprons) might make up the seat system of a simple chair design.

Step-2: Identify the failure modes of each system

When a design falls short of user expectations and/or intended functionalities, among other criteria, it is said to be in a failure mode. Given that one of the seat system’s functions is to support the user’s weight, breaking seats would be one of the failure modes for this system.

Step-3: Describe the potential effects of each failure mode and assign severity rating

A failure mode’s immediate result is known as a failure effect. A broken seat could cause injuries to users, the chair to fall, and exposed sharp edges to become visible. These failure consequences on customers should have a severity rating based on predetermined criteria. An effect with a severity value of 1, for instance, indicates that there would be little to no influence on customers, whereas an effect with a severity level of 10 indicates that there will be an impact on customers’ safety or compliance with regulations.

Step-4: Determines the potential causes of each failure modes

Examine the primary cause(s) of the failure mode after assigning a severity grade to a failure effect. Sometimes component function issues, such thin seats, flimsy aprons, sheared corner blocks, and loose fasteners for the failure mode “seat breaks,” are the root cause of design faults.

Step-5: Specifies prevention controls and assign occurrence rating

Preventive controls for DFMEA are targeted actions taken to stop failure causes from occurring. Remember that they are references to preventive, or current, actions. Depending on the likelihood that a failure cause would persist after the implementation of preventive measures, an occurrence rating ought to be allocated. The scale for occurrence ratings is likewise one to ten, where a score of one indicates that the cause is extremely improbable or almost impossible to occur even with continuous preventive measures, while a score of ten indicates that the cause is almost guaranteed to persist and produce an impending failure.

Step-6: Assign a detection rating and indicate detection controls

DFMEA detection controls are now in place and were put in place to enhance the capacity to identify the root causes of failures prior to the completion of design drawings and specifications. Customer reviews, durability tests, and visual inspections are examples of current detection efforts. Regardless of the techniques, these metrics should be rated according to how likely they are to identify the root causes of failures. A detective control that has a score of 1 indicates that it can almost definitely identify the source of a failure, whereas a score of 10 indicates that a failure cause might remain hidden even in the presence of continuous controls.

Step-7: Calculate the Risk Priority Number (RPN)

Teams in DFMEA generally utilize a risk priority number to assist them in prioritizing which design failure modes to address. Multiply all three DFMEA scores (severity, occurrence, and detection) to obtain the RPN. It is crucial to understand how the DFMEA rating functions in relation to the other figures. Assuming that three distinct failure modes with RPNs of 60, 120, and 30, respectively, it may be more prudent to address the second failure mode, which has RPN 120, first. The decision-making process for which failure modes to address can also be streamlined by using a predefined RPN threshold value (e.g., 100 and above).

Step-8: Create the high-priority recommendations

The responsible staff should be assigned recommended actions with target completion dates upon identification of failure modes with RPNs above the limit. Consider methods to lessen the impact of failures or whether implementing new preventative and investigative procedures can lower the scores for occurrence and detection when determining what steps should be taken.

Step-9: Document actions taken

Things might not go as planned, even if Design Failure Mode and Effects Analysis can methodically offer wise recommendations. Whatever steps are done, they must be recorded along with the precise date of completion. To aid teams in following through and properly tracking their development, the DFMEA form should also be updated appropriately.

Step-10: Re-analyze RPNs to decide next steps

Finally, since the design has been improved, the risk priority numbers of the target failure modes need to be recalculated. The design can proceed in the product development process once the team certifies that all risks have been addressed by the modifications made.

Manufacturing

DFMEA examines potential safety concerns, product life issues, compliance challenges, and probable malfunctions in the product. DFMEA can be used in the manufacturing sector to investigate material qualities, tolerances, and component and system interactions. DFMEA can assist in locating problems before they become expensive to fix.

Performing a DFMEA Audit

There are various ways to approach the DFMEA process, depending for your business and industry. Here are some easy steps to follow so that your organization can perform a DFMEA audit.