Matthew Woodford, with a 45-year tenure in the motor industry, delves into Failure Mode and Effects Analysis (FMEA), a key element in engineering and manufacturing. FMEA aids in anticipating failures, enhancing product robustness, and improving process efficiency. FMEA is a dynamic risk management framework applicable to daily life, ensuring consistency and fostering collaboration among engineers.
In manufacturing, FMEA and its reverse variant enhance safety and process robustness, contributing to smarter engineering practices. Reverse FMEA stresses processes to uncover weaknesses, reinforcing process robustness. Embracing FMEA as a "living document" aids in ongoing improvement and professional growth. FMEA is a tool for personal and professional growth, encouraging engagement with documentation to expand understanding. Conducting comprehensive FMEA before major expenditures helps prevent costly modifications and delays. Improve engineering and manufacturing practices through effective risk management and failure anticipation.
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By Matthew Woodford
Introduction
With 45 years of experience in the motor industry, I aim to share some of the benefits and knowledge I have acquired and pass it on to others. I would like to discuss one of my favourite software tools in the quality system arsenal, which is FMEA. I want to demystify what an FMEA is, explain its benefits, and illustrate how it can enhance you as an engineer or technician. When utilized correctly, this tool can empower you. Whilst there are various FMEA types, such as Reverse FMEA and Systems FMEA, the core concept remains the same: analyzing failure modes and their effects. This is the essence of Failure Mode and Effects Analysis (FMEA).
Design FMEA
We can conduct a design FMEA, where the designer working on the product evaluates the strength of the design. The purpose is to determine if a failure in this aspect of the design would, for example, endanger a person's life or whether such a failure would leave the end user dissatisfied by compromising the primary function or purpose of the part being designed and developed. By performing a thorough design FMEA, we can then proceed to review our process FMEA.
Process FMEA
A Process FMEA follows the same approach as a Design FMEA but is utilized to assess our manufacturing process. Outputs from our manufacturing process are directed towards tasks such as control plans, preventive maintenance, and machine tender documents. There are specific outcomes associated with this analysis.
FMEA in Real-Life
Performing an FMEA is a natural process that we all engage in unconsciously. There is no hidden or mysterious aspect to conducting an FMEA; it is simply a methodical risk assessment tool. This structured approach involves following specific steps, breaking them down, and evaluating the outcomes, a practice that is ingrained in our daily routines.
For instance, when embarking on a long journey, such as a thousand-kilometre road trip that has been meticulously planned, considerations about potential risks are automatically present in our subconscious. Questions like whether the car has been serviced recently, the timing of the last service, and the need for another service before the trip naturally arise. Anticipating possible failures like a breakdown during the journey is part of this subconscious risk analysis. To ensure a smooth trip, it is advisable to send the car for servicing, check the oil level, inspect the radiator for leaks, confirm the antifreeze mixture, and assess the condition of the tyres. With only 800 kilometres of tyre wear left, it would be wise to replace the tyres to ensure a successful trip. The goal is to reach the destination and return without any issues. This involves planning and preparing the car, fueling it up, and driving safely to the destination. Anticipating potential problems during the journey is known as Failure Mode and Effects Analysis (FMEA), in a very simplistic format. By examining the functions and steps of the journey, one can identify possible risks and take preventive measures, such as checking the spare wheel and ensuring it is in good condition before departure. This proactive approach helps mitigate any potential issues that may arise during the trip.
FMEA in Industry
In the automotive and manufacturing industries we implement a structured process based on the fundamental concept of FMEA. This structured approach ensures consistency in how FMEA is applied by everyone involved. Instead of having different versions from different individuals, our standardized approach allows for a clear understanding and interpretation of any FMEA document within the automotive industry.
Furthermore, with a structured approach, we are guided through a distinct series of actions. By following these progressions we can scrutinize each step to comprehend their purpose. For instance, it is essential to evaluate the process flow meticulously. This involves moving from one operation to the next in a systematic manner, foreseeing potential outcomes through FMEA analysis before making significant investments. By getting the FMEA right, we can effectively communicate our requirements to machine suppliers, which is a key advantage of this approach over mere checkbox exercises. Understanding the planned process is crucial as we progress through each step sequentially, deconstructing them into functions to determine their intended role.
We have inputs for a process. These inputs consist of your five M's: man, machine, material, method, and mother nature. All these inputs are utilized in your method. If you are baking a cake and you have the correct mixture and sequence for adding the elements, we anticipate a result. The result should be a delicious, succulent cake that is not overcooked, tough, dry, or crumbly unless we are intentionally designing a crumble, which would be part of your Design FMEA! Therefore, we have a process FMEA. We have dissected that stage into inputs and anticipated outputs, for example, we aim to reach our destination on our car trip. In our process, we anticipate specific outputs that we identify and by breaking down these functions into elements and expected outcomes, we can test these outcomes.
Thinking About Failure Modes
When we ponder the familiar question of what could go awry, we may find ourselves contemplating the possibility of not achieving a desired outcome - that would be our failure scenario. Have you ever visited B&BS, hotels, or similar accommodations? We all crave that perfect golden-brown toast to complement our breakfast. Placing it in at the top of the toaster, we watch as the toaster whirls, clicks, clunks, and eventually delivers the toast from the bottom - still white! I like golden toast, so I put it on the top again for a second run. Only this time it comes out burnt at the bottom! I don't want
that so I put it in the bin. That's a wasted piece of bread and an unnecessary expense gone down the drain.
My process for making golden brown toast didn't succeed. The expected result of inserting a piece of bread at the top is a nicely toasted piece at the bottom, which is my anticipated outcome. What can go wrong? It's not golden brown. There are two failures: it's burnt and black, or it remains the same colour as when it was inserted (i.e. it's not toasted). These are the failure modes.
For each failure mode identified in our process, the next step is to question it and determine why it occurred. Why did it end up burnt? What measures should I implement to prevent this from reoccurring? Every time it happens, a burnt slice of bread is wasted. I need to evaluate my process and expected outcome. If I'm not achieving it, that's my failure mode. Now, what preventive measures can I implement to avoid encountering that failure mode? That's when you establish the correct settings for speed and temperature.
I have been purchasing machines from various countries, including Japan, and one particular machine I acquired was a rotary transfer machine. If you are reading this, you should have some understanding of manufacturing processes. This rotary transfer machine required special procedures for changing tools, involving large and heavy cutters being swapped in and out. While I was there, a thought crossed my mind - could I accidentally damage the machine while they were changing the tooling? So, I asked my Japanese colleagues and engineers if the table would rotate if I pressed the "index table" button on the control panel while they were removing a cutter. They were taken aback and expressed concern, saying it would be foolish and unsafe! I acknowledged the danger but inquired if the table would rotate if I activated the control. They discussed amongst themselves and returned confirming that indeed the table would rotate. I then requested a safety control to be implemented not just to protect the part's integrity but also to ensure the operator's and setter's safety, a crucial aspect in Failure Mode and Effects Analysis (FMEA). The team left and returned with new PLC logic for the controller and upon pressing it, the rotary table did not move, which was the desired outcome.
Reverse FMEA
There is a concept emerging in FMEAs known as reverse FMEA. Different customers, such as Ford, General Motors, and Volkswagen, have varying interpretations of reverse FMEA. However, it is crucial to understand that a reverse FMEA is not an afterthought! By the time you have your production line set up, it may be too late to perform an FMEA. This is because the FMEA should be conducted before purchasing a machine. The findings of an FMEA, including the necessary controls, should be integrated into your tender documentation for potential machine suppliers. By sharing the identified potential failures from your process FMEA with the machine supplier, you are essentially informing them about the specific risks that could lead to nonconforming parts. It is essential that the machine supplier addresses these issues in their own FMEA, incorporating the outputs from your process FMEA into their machine controls.
Having been a Ford employee for many years, they encourage you to experiment. Once your process is approved, it undergoes all the necessary launch controls, and you move into series production. After 12 months they reassess the improvements you have made to enhance the robustness of your process. They expect to see a detailed plan that identifies and prioritizes the machines, including those that may pose constraints or act as bottlenecks, and those with the most critical characteristics. You should have conducted tests to identify potential failures and defective parts, with controls in place as outlined in the FMEA and control plan to detect and prevent any issues. They are now considering performing a reverse FMEA. What other modifications or scenarios could be tested on the machine that were not previously considered during the initial FMEA analysis? What would be the outcome if the part is inserted upside down? How would the machine react if the tool changer mistakenly selects the wrong tool? Is it possible to load the part backwards, and if so, would it cause any damage to the machine? Will the machine continue to operate normally in this situation?
When we caution against acting recklessly or tempting fate, we must remember that in manufacturing and the automotive industry, Murphy's Law often applies - if something can go wrong, it will! It is crucial to anticipate and prevent potential failures before they occur. For Ford, the reverse FMEA approach involves deliberately testing processes and operations to identify weaknesses. This proactive strategy involves documenting and preserving results as evidence for audits. By outlining a plan to systematically assess machines and establish priorities, companies can mitigate risks and prevent costly mistakes. This meticulous approach is a key aspect of reverse FMEA.
When addressing other customer-specific requirements, your reverse FMEA analysis could be guided by your quality matrix, the data obtained from your quality feedback, warranty information, customer complaints, and G8Ds. It is important to address these quality issues and question why the FMEA process did not prevent them. Revisiting your FMEA and conducting an audit on it is crucial. The FMEA should have indicated the possibility of these issues occurring and confirmed that the necessary measures were in place to prevent them. However, despite having a control plan outlining detection and protection measures, the customer was not safeguarded. If the customer had been protected, the need for a corrective action process like the 8D system would not have arisen, which is typically initiated when a customer receives a faulty or defective part.
Benefits of an FMEA
Performing an FMEA does not guarantee that you will have the most resilient process, but if done correctly, it can eliminate 99% of potential failures. Simply checking the box is not enough. An FMEA is designed to optimize time and cost in a process. Making changes to your machinery, process, or equipment after purchase and installation will lead to project delays, time penalties, and possibly the need to hire more resources to mitigate these setbacks. Ultimately, it will incur costs. Conducting an FMEA before making capital expenditures can result in significant cost savings.
Conclusion
When striving for personal growth, the desire to progress and acquire knowledge is natural. An FMEA serves as a wealth of information. If your FMEA is robust and reliable, you should seek to understand the process and the organization you are part of. Review, comprehend, and question the FMEA as it holds a vast amount of knowledge for everyone's benefit. I believe that FMEAs are among the best-structured systems in manufacturing, particularly for those involved in process or project engineering. I have immersed myself in FMEAs, finding them stimulating and a valuable part of my ongoing learning journey.
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