By: Virginia Shram
January 29, 2024
No matter the industry, manufacturing processes can sometimes fail in thousands of different ways. This makes it difficult to determine the exact cause of a failure when it occurs.
Luckily, there are comprehensive methods of tracking and investigating failures for more reliable manufacturing. While you can never fully eliminate the possibility of failure, conducting a proper failure analysis can help put you back on track to continuous improvement.
Let’s break down the elements of failure analysis.
If you truly think about it, there are nearly infinite possibilities for a manufacturing failure, from miscalculating a measurement to a meteor falling on your production line (although we acknowledge that last possibility is very, very unlikely).
In fact, failure doesn’t have to be disastrous, like a machine breaking down and pouring smoke. Failure can also include a final product that doesn’t quite pass final quality checks. That being said, we should try to find some way of classifying types of failures in a very elementary sense so that they can be examined in more depth as you conduct your failure analysis.
Internal causes of failure are factors that are within your control. This doesn’t mean that they are necessarily anyone’s fault or mistake – just that they are potentially fixable within your immediate environment.
Examples of internal causes of failure include:
External causes of failure are factors that are outside of your control as a manufacturer.
Examples include:
Oftentimes internal causes of failure are more easily addressed than external causes of failure. The main thing to take into account is that all of these factors can interplay with each other to various degrees, and it is crucial to acknowledge the full extent of possibilities when conducting your failure analysis.
For example, there are tried and true ways to reduce the potential for human error, just as there are incident report metrics to track the overall rate of error. You will probably need a combination of both tools.
Don’t worry about trying to label your potential failures as internal or external just yet. You don’t have all the pieces of the puzzle, which is why we’re going to introduce several tools to help you gather all the evidence for your failure analysis.
In order to uncover root causes of failure, you have to think like an investigator. Tools alone aren’t going to do the hard work of analyzing your workflows, so don’t just go through the motions. Remember to be diligent and fully observe all the working parts of your manufacturing business.
Experts in failure analysis nurture the following skills to help in truly revelatory failure analysis:
Try reminding yourself of the DMAIC approach to improve your analytical reasoning skills.
The industry standard for assessing modes of failure is a tool called FMEA, which stands for Failure Mode and Effects Analysis.
There are 10 steps in a Failure Mode and Effects Analysis (FMEA):
Here are a couple of templates you can use for your own FMEA:
You can use several other tools in combination with an FMEA chart to help with analyzing potential manufacturing failures.
This is just a small overview. If you want more detailed information about any of the below tools, be sure to click on the included hyperlinks to read our other articles about how and when to use them in your failure analysis.
Root cause analysis is the practice of uncovering the core issue – the root cause – of a problem or error in a process. It is a collaborative process of problem-solving by interrogating the situation at hand. There are many types of root cause analysis, and the two most commonly used, Ishikawa diagrams and the 5 Whys, are described below in more detail.
Quality Function Deployment is a comprehensive plan for setting up lean operations, with blueprints for production processes, marketing and sales, distribution, etc.
It is common for FMEA charts and QFD blueprints to co-exist as a master plan for lean-ifying manufacturing plants. In fact, it is recommended that FMEA charts are applied after setting up your factory for QFD.
The 5 Whys is a root cause analysis tool that uses questioning as a way of uncovering more detail about a situation. It works due to its repetition: by asking the question “Why” 5 times, you examine deeper issues at play that contribute to failure, as opposed to focusing on the surface problems. Here is an example:
Ishikawa diagrams, also known as Fishbone diagrams, are charts that aid in root cause analysis by separating and classifying any potential problems on a line diagram. It is an orderly method of cataloging many issues that contribute to an eventual failure. When completed, the diagram resembles a fish skeleton: