Wednesday, January 15, 2020

FMEA | Failure Mode and Effect Analysis | QSQTECH.COM

FMEA (Failure Mode and Effect Analysis):

Hello friends, 
Today, we will talk about FMEA (Failure Mode and Effect Analysis).
Lets, we try to understand this concept. 

Failure Mode and Effect Analysis

Some important topic, that we are covering today: 
  • Process FMEA 

You will understand hopefully. 


As we know, there are five core tools in quality management system. In which FMEA is very important core tool. 


FMEA (Failure Mode and Effect Analysis) is a way to identify and analysis the failure modes and their resulting effects in system, design or manufacturing process. 
It is a proactive approach in which the failure modes, and their effects are already identified and take action on it so that possibilities of failure can eliminate from system or manufacturing processes. 


By the way, the concept of identifying the failure modes was in the minds of people for hundreds of years. But it was used formally in 1960, by the American aerospace company NASA. When NASA working on the Apollo program, it made perfect use of the FMEA concept. NASA thought that if we remove all probable failures in advance and action on them in advance, our chances of success will increase. In this way, first time, NASA used the FMEA in its aerospace company. Later, it was adopted in the automotive industries in the 1970s. At that time it was incorporated as a system/as a requirement in the QS-9000 and Advanced product quality planning process of quality management system of automotive industries. Now seeing the success of FMEA, industries other than automotive have also using it rigorously. It is known by different names in different industries by fine-tuning it.


  • Identify design / process related failure mode before they happen. 
  • Identify the severity and effect of those defects. 
  • Identify the causes of failure and probability of occurrence of failure mode also identified. 
  • Understand its control and effectiveness. 
  • Quantifies the risk, and after that it priorities also. 
  • And then, document the action plan and implement it. 


1. Failure mode:  

It means that what is the probability of failure in the process. That is, in what ways can the process fail. 

2. Failure mode "Effects": 

It is basically that what would be the effect if failure mode occurs.  

3. Severity Ranking: 

It is basically identifying severity of effects of our potential failure mode. 

4. Failure mode "Causes": 

It means that if it fails, what are the reasons for its occurrence?  

5. Occurrence Rating: 

It is basically an estimate of what the frequencies are likely to be when a failure occurs. 

6. Failure modes "Control": 

It means that what is the current mechanism or what method is there to control failure modes. What is the test procedure or what type of control mechanism is available. 

7. Detection Rating: 

It means that if it fails, then how much probability is made in my detection process that if it fails, it will be discovered. 

8. Risk Priority Number (RPN): 

It is multiplication of severity, occurrence and detection.                                                            
RPN = Severity × Occurrence × Detection 

9. Action planning: 

In action planning, we do an action that I can reduce the risk by improving the different elements that are in my severity rating, occurrence rating, and defection rating. So, we can reduce the severity rating, occurrence rating and detection rating and try to reduce its impact. 


We are going to understand Process FMEA in detail, so following we will understand its 9 steps. 

Step:1  Describe Process:
Describe process
To do Process FMEA, First, you must have a process diagram as input. Is means that it is very necessary to under the process, sequence wise. Apart from this, the team should also have some other backups. For example, the error and correction data of similar parts or process in which the defect has occurred in the past or any error has been found and its correction data should be there. Data of internal and external problem should be there. It is mandatory to keep all such of backups to you. 

Step:2  Define Functions:
In this step, we try to tell the function, what is the functions that are performed in the process. 

Step:3  Identify Potential failure mode:
In this step, we identify the failure in the functions. That is, what is the failure, and what could be reason for failure. 

Step:4  Describe Effects of failure:

  • Effects of failure means that what will be the effect if there is a failure. It is very necessary to understand that the effect that will happen, don't just have to see the immediate effect. That is, we have to see what the effect will be in the next operation. 
  • Subsequent downstream operation i.e. what will be the effect in upcoming operation. How will affect the customer 
  • Immediate delayed impact: It means that if you are in the automotive industry, you do not just have to see what will the failure at customer end. You have to see that if the vehicle is running in the field after the vehicle is built and if it fails in its lifetime then what could fail, and what will be its impact. We have to think about that level here. 

Step:5  Determine Causes: 
It means that if there is a failure, then what probable causes can be there. We have to identify those potential causes where we have to tell very clearly that what is the actual cause. Here we don't have to keep in mind symptom. If we take the symptoms into mind then we will have to take trouble. 

Step:6  Current Control: 
In order to preference, there are three types of current control.
  1. Prevent causes 
  2. Detect the cause, leading to corrective action 
  3. Detect the failure (Defect)

These might include: 
  • Control charts 
  • Check sheet 
  • Mistake proofing 
  • Training 
  • Information technology 

Step:7  Calculate Risk: In this step, we multiply the severity, occurrence and detection and the number that comes out after multiplying is called RPN (Risk Priority Number). 

RPN Number = Severity of the effect × Probability of Occurrence × Detection (Capability of current control

Step:8  Take Action: 
After calculating the RPN, the next step is action taken. In this step, the action is taken to reduce the RPN.
After action implementation, FMEA is again review so that effectiveness is find out and find out the severity, occurrence and detection. Do not modify the RPN until you do the action implementation.

Step:9  Asses Results: It means that I have asses what happened in the ranking after taking my corrective action. 

We hope you will understand this topic. 

Thank you 😊
 Some of a related question that help to improve your basic knowledge. 

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