Lean Six Sigma Green Belt Certification FMEA
FMEA is a proactive tool to prevent mistakes and errors in the processes and design. When you are doing something for the first time and don’t have enough data to quantify the risks of failure, FMEA can be used. Risk management is the process of identifying, assessing and controlling threats to an organisation’s capital and earnings. Risk reduction or “optimization” involves reducing the severity of the loss or the likelihood of the loss from occurring. FMEA serves this purpose. FMEA is a tricky topic and needs concentration. Read this article to understand everything about FMEA. A video on our website is also available explaining the tool.
Read this blog to understand topics like severity ranking, potential causes, prevention controls, testing, detection controls and a lot more. The tips given below are specially designed by industry experts who have 30 years of experience. Read the blog carefully to grab a deep insight on FMEA.
FMEA – How to solve & tips
There are a total number of 12 tips to complete FMEA correctly. These tips were created by experts and they are as follows
- Developed in the 1950s, FMEA was one of the earliest structured reliability improvement methods. Today it is still a highly effective method of lowering the possibility of failure. Failure Mode and Effects Analysis (FMEA) is a structured approach to discovering potential failures that may exist within the design of a product or process. Failure modes are the ways in which a process can fail.
- Effects are ways in which these failures can lead to waste, defects or harmful outcomes for the customer. Failure Mode and Effects Analysis is designed to identify, priorities and limit these failure modes.
- FMEA is not a substitute for good engineering, rather it enhances good engineering by applying the knowledge and experience of a Cross Functional Team (CFT) to review the design progress of a product or process by assessing its risk of failure. One can say that it is a systematic method for identifying possible failures that pose the greatest overall risk for a process, product, or service which could include failures in design, manufacturing or assembly lines.
- FMEA is classified into Design FMEA (DFMEA) and Process FMEA (PFMEA).
- Design FMEA (DFMEA) is a methodology used to analyze risks associated with a new, updated or modified product design and explores the possibility of product/design malfunctions, reduced product life, and safety and regulatory concerns/effects on the customer.
- They are derived from: material properties (Strength, Lubricity, Viscosity, Elasticity, Plasticity, Malleability, Machinability etc.), geometry of the Product (Shape, Position, Flatness, Parallelism, tolerances/stack-ups, interfaces with other Components and/or Systems (Physical Attachment/Clearance; Energy Transfers; Material Exchange or Flow i.e. Gas/Liquid; Data Exchanges – Commands, Signals, Timings), and engineering Noise including User Profile, Environments, Systems Interactions & Degradation.
- Process FMEA (PFMEA) is a methodology used to discover risks associated with process changes including failure that impacts product quality, reduced reliability of the process, customer dissatisfaction, and safety or environmental hazards.
- They are derived from the 6Ms, man: human factors/ Error, methods: methods involved in processes of product/service including assembly lines, supply chains and communications standards, materials: materials used in the process, machinery: machines utilized to do the work, measurement: measurement systems and impact on acceptance, and mother earth: Environment Factors on process performance.
- FMEA is one of many tools used to discover failure at its earliest possible point in product or process design. Discovering a failure early in Product Development (PD) using FMEA provides various benefits.
- Multiple choices for mitigating the risk, higher capability of verification and validation of changes, collaboration between design of the product and process, improved design for manufacturing and assembly (DFM/A), lower cost solutions, tribal knowledge, and Standard work utilization are some of the benefits of FMEA.
- Ultimately, this methodology is effective at identifying and correcting process failures early on so that you can avoid the nasty consequences of poor performance.
- FMEA provides a structured approach to identifying and prioritizing potential failure modes, taking action to prevent and detect failure modes and making sure mechanisms are in place to ensure ongoing process control. FMEA also helps document and identify where in a process lies the source of the failure that impacts a customer’s CTQ’s.
How can FMEA be used?
Target a bottle neck and focus on a failure mode the team needs to eliminate. Once each failure mode is identified, the data is analyzed, and three factors are quantified:
- Severity (SEV): The severity of the effect of the failure as felt by the customer (internal or external). The question may be asked, “How significant is the impact of the effect on the customer?” Severity of 1 denotes low risk to the end customer, and a score of 10 denotes high risk to the customer.
- Occurrence (OCC): The frequency at which each failure or potential cause of the failure occurs. The question may be asked, “How likely is the cause of the failure mode to occur?” Occurrence of 1 denotes low probability of the risk happening, and a 10 denotes a very high probability of the risk happening.
- Detection (DET): The chance that the failure will be detected before it affects the customer internal or external). The question may be asked, “How likely will the current system detect the failure mode if it occurs, or when the cause is present?” Detection of 1 denotes a process that WILL likely catch a failure, and a 10 means the process will likely NOT catch a failure.
Each of the three factors is scored on a 1 (Best) to 10 (Worst) scale. The combined impact of these three factors is the Risk Priority Number (RPN). This is the calculation of risk of a particular failure mode. The information inputted into an FMEA is calculated, and the output is a Risk Priority Number (RPN). The RPN is calculated by multiplying the severity times the occurrence times the detection (RPN = Severity x Occurrence x Detection) of each recognized failure mode. With the table given below you can get a better idea about it.
|Failure Modes||Severity (1-10)||Occurrence (1-10)||Detection (1-10)||RPN|
Also read: Lean Six Sigma Green Belt Certification Control Charts
FMEA- Example exercise 1
RPN in FMEA stands for
FMEA- Example exercise 2
Which Six Sigma tool uses RPN?
FMEA- Example exercise 3
If severity =5, Occurrence = 4, Detectability = 2, what is RPN?
FMEA- Example exercise 4
_ is the probability of the failure being detected before the impact of the failure to the process
Answers for skills building exercises
Answer for the first sample exercise is : FMEA RPN (Risk Priority Number) is a numerical assessment of the risk priority level of a failure mode in an FMEA analysis. FMEA RPN helps the responsible team/individual to prioritize risks and make the decision on the corrective actions.
Answer for the second sample exercise is : FMEA RPN (Risk Priority Number) is a numerical assessment of the risk priority level of a failure mode in an FMEA analysis.
Answer for the third sample exercise is : Risk Priority Number = Severity x Occurrence x Detection.
Answer for the fourth sample exercise is : Detectability is often defined as the ability to detect a failure before it causes harm.