Out worst fear in design is to end up with a failed product. At this particular moment, we pause and wonder; if we would know this will going to happen, we could have taken another route. The Failure Modes and Effects Analysis (FMEA) tool helps us to understand the potential risks that may occur when the designed product or service is used by the consumers and provide suggested methodologies to prevent it in an early stage of the design process.
The Failure Mode and Effects Analysis provides a proactive method that allows us to evaluate both the design and the process to learn more about when, where, and how the failure may occur. Also, it shows us the failure impact on different parts of the process through prioritizing the risks using three main value; the severity of the risk, its occurrence, and ability to detect it. Then, the team can apply problem-solving tools such as TRIZ or 8D Problem Solving Approach.
- Problem-Solving Using Cause and Effect Diagram
- Using the TRIZ Method for Creative Problem Solving
- Practice Guide to Solve Problems with TRIZ
The Failure Mode and Effects Analysis was first introduced by the U.S. Department of Deference in 1949 and it is now widely used in quality control and it is built on other tools such as the Risk Analysis and the Cause-Effect diagram. It can be used in both the product development process and business design process.
Types of the Failure Mode and Effects Analysis (FMEA)
The Failure Mode and Effects Analysis can be categorized based on the target part of the production. So, we can categorize the FMEA to the following types:
- Design FMEA explores the product malfunctions that is related to the materials, form, interface component and engineering. These failures that may affect factors such as the product life cycle and safety.
- Process FMEA explores the faults that related to the production process that includes the manufacturing and bringing all the industry components together
- Functional FMEA explores the faults in the how the global system functions
- Service FMEA involves the service design associated with the product
- Some added more types to the above list such as the System FMEA and the Software FMEA. However, the above categories can cover all the possible types of the Failure Mode and Effects Analysis.
Applying the Failure Mode and Effects Analysis
The Failure Mode and Effects Analysis is applied in different stages of the product for example at the beginning of a new production process, applying changes to an existing product or the production process, applying new production regulations, and of course to solve a problem reported by the consumer about the product.
The application of the Failure Mode and Effects Analysis can be done through a number of procedures that are organized in a table as follows:
Define the product that will be analyzed and its function. This will help us to focus the investigation into this particular product or service. For example, car seat belt.
Define the first potential failure that may occur in relation to the product design and process. Each potential failure should be listed individually to avoid distraction and misleading information. In the best example, it is hard to release in time for emergencies that require leaving the car immediately such as drowning or fire.
Determine the severity level of the fault effect. The standard scale is from 1 to 10, where the 1 refers to no effect and 10 means a very example failure affects the product or system without warning. In our example, the severity level is 10.
Add the potential cause or causes for the failure. For example, the design of the seat belt lock, the functionality of the lock and how easy to open it when the user intends to do that.
Add the probability factor which represents how many time this failure is likely to happen. Again, the common scale is from 1-10, where 1 means that the fault is not likely to happen and 10 means that high probability to occur. In this case, the probability will be 3 as it is assumed that is a lower number of accidents that may occur and requires an immediate release to the seat built.
Identify the current procedures that the system is using to prevent such failures from happening such as testing, monitoring, or applying error-prevention mechanisms. For example, the current lock is designed to easy release, its red color allows the user to easily identify it.
Determine the detection value for the fault. It represents the likelihood to detect the failure using the current control methods. We use the scale of 1-10 to determine the detection value. However, it is a reversed value comparing with the above factors. This means that 1 refers to that the error is likely to be detected using the current controls and mechanism. The 10 value means that the fault is not likely to be detected. In our example, we will set the detection value to 7 as the testing mechanism may not involve testing how the drivers release the belt during the time of accidents.
Define the Risk Priority Number (RPN) for failure. The RPN is an equation that includes multiplying the above three factors to prioritize the faults decide and understand the importance to solve it. The RPN equation is:
Risk Priority Number (RPN)= Severity x Occurrence x Detection
In our example, the RPN= 10 X 3 X 7= 210
Determine the recommended actions that can be applied to prevent this failure in the future. This may involve changing the current controls or improving it to make sure that the detected failure will not occur again in the future. For example, change the position of the lock to make it easier to release during the time of emergencies.
Assign the responsibility of applying the recommended procedures to a person in order to build an action plan to apply these recommendations within the current system structure.
Repeated the above steps with each detected failure. Using the Risk Priority Number, you can determine which fault is more sever than the others and which one to start solving immediately.
The table above shows a complete Failure Mode and Effects Analysis that are done to explore solutions for a number of failures in a product. You can use it as a template for future FMEA tasks.
The Failure Mode and Effects Analysis provides a systematic method to detect, analyze and provide a solution for failures that may occur on multiple levels of the production process. It helps the team to indemnify the weak points in the product, process, or system and try to overcome it over the course of improving the production process and subsequently the final product or service.