Root Cause Failure Analysis
In this post on Root Cause Failure Analysis we will discuss about the fundamentals and procedures to carry out the root cause failure analysis. To minimize the losses and down time of machines, a root cause failure analysis is the best tool.
What is Root Cause Failure Analysis?
The systematic method of series of actions taken and reviewing all the evidence to find out the causes and correction of the failure and the existing problem is known as Root cause failure analysis (RCFA). The root-cause analysis also determines the manageable root causes and prevents recurrences of failures and problems.
Root Cause Failure Analysis Purpose
Most of the problems and failures that prevail are deep-rooted.
There are recurrences of problems and failures.
These deep-rooted problems are 20% and cause 80% of losses. It is imperative to understand this fact while considering the advantages of Root failure analysis. The investigations and of these deep-rooted problems will reduce the maximum losses enhancing the production or operational capability. These are only a few failures called as few failures significant failures.
Root Cause Failure Analysis should start upon the identification of the important few failures.
Adopt the following process to conduct the Root Cause Failure Analysis.
- Preservation of failure Data
- Calling for analysis
- Data analyzing
- Communicate the findings with the management for further decision.
- Follow up on the success of RFCA.
Preservation of failure Data
Data maintenance is the most effective factor in analysis. All the broken parts, data readings (log book readings) need preservation. Adopt the standard data collection procedure. List of required category of information
- Involved Personnel ( People)
- Damaged Parts
- Papers (Records etc.)
- Position ( Location )
An analyst must interrogate the people and interview the people involved in the data collection.
Calling for analysis
It is not possible to analyze a problem without the involvement of experts in a particular field. Better to follow right person for the right job principle for the Root cause failure analysis.
The team should consist of a chief analyst to facilitate the project of Root cause failure analysis.
Team also should have a team of experts with the panel of the analyst.
Define the objective of the team to create the team focus for the proper root cause failure analysis.
Define clear rules and guidelines for the analyst team to follow.
Start analyzing the problem once the team is assembled and has collected the critical data.
Adopt a standard logic procedure to help the team to focus on the problem.
Follow the following components to analyze the root cause.
- Failure event starting
- Failure mode starting
- Verification of Brainstorming.
- Concluding the underlying causes of Physical, Human, and Latent nature.
The team should ask the How could question for their conclusion.
For example,-our failure model has failed piston, and then our assumption will be fatigue, overload, overheating, hydraulic lock, over speeding, and lubrication oil failure. Use the data for approving or disapproving the hypothesis.
After the proven and disproven, assess causes of problem-related to physical, human, or latent.
Communicate the findings with the management for further decisions.
On completion of the search for the root causes, communicate the results with the management for making the decisions.
Submit detailed reports of findings for the justifications and understanding of your fair analysis.
Your report should be compelling and comprehensive so that the management is forced to implement the solutions.
Speculating that your communication with the management was fruitful, it is advised to track the success of your recommendations to ensure to receive the return on investments that you have anticipated.
Take the following measurements.
- Minimized maintenance cost
- Enhancement in production capabilities.
- Minimized the rate of failures.
An important tool for Root cause failure analysis
We will discuss below the common analysis tools
- Pareto Diagram
- The 5 whys
- Fishbone diagram
- Scatter Diagram
The Pareto Diagram method exists universally in the manufacturing process. The Pareto diagram is a simple and powerful diagram. A Pareto diagram helps in identifying the waste in the process and helps in conducting root failure analysis.
This rule is 80-20 rule as explained below.
- 80 % of the tasks in the department are completed by 20% of the people
- 80% of the faults in a production process are by 20 % of its machines.
- 80 % of problems in an establishment result from 20 % causes.
- 80% of the inferior parts are the supply by 20 % of suppliers.
As per the data analysis following findings has been recorded.
- Disappearance of parts
- The disappearance of tools and tackles.
- Unsuitable parts
- Blockage in lines
- Issues of maintenance
The 5 whys
This program of analyzing a problem is part of the Toyota productions system. As per this program
Example of applying 5 Whys
- Why the delay in the maintenance of the machine? Spares were not available beforehand.
- Why were the spares not available beforehand? Because spare part ordering was late.
- Why the delay in ordering the spares? Because complete offer from the vendor was not available
- Why vendor didn’t submit the quotation in time? Because our inquiry of spares was incomplete.
- Why our inquiry of spares was incomplete? Because the newly joined purchase executive didn’t have complete knowledge of parts and machines.
The best tool used for the Root cause failure analysis is fish bone diagram.
Conditions for the use of Ishikawa diagram
- Root cause of problem identification.
- When the team is not able to analyze the causes.
The procedure of the Fishbone diagram
- Marking pen
- Agree with the problem effectively. Write the problem centre-right of the whiteboard. Enclose the problem with the box and draw an arrow in a horizontal direction running to it.
- Carry out the brainstorming for the categories of problems.
- Write the causes categories as the arrow branches.
- Carry out the brainstorming for the possible causes of the problem. Write down the reason for the problem in several places.
- Ask for the reasoning of each cause of the problem
- Focus the attention to place the ideas on the chart.
The Best Book On Engine Failure Analysis
Engine failures result from a complex set of conditions, effects, and situations. To understand why engines fail and remedy those failures, one must understand how engine components are designed and manufactured, how they function, and how they interact with other engine components. To this end, this book examines how engine components are designed and how they function, along with their physical and technical properties.
Translated from a popular German reference work, this English edition sheds light on determining engine failure and remedies. The authors present a selection of engine failures, investigate and evaluate why they failed, and provide guidance on how to prevent such failures. A large range of possible engine failures is presented in a comprehensive, readily understandable manner, free of manufacturer bias.
The scope of engines covered includes general-purpose engines found in heavy commercial vehicles, railway locomotives and vehicles, electrical generators, prime movers, and marine engines. Such engines are technical precursors to automotive engines.
This book is for all who deal with engine failures: those who work in repair shops, shipyards, engineering consultancies, insurance companies and technical oversight organisations, as well as R&D departments at engine and component manufacturers. Researchers, academics, and students will learn how even the theoretically impossible can–and will–happen.
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