Showing posts with label methods of rca. Show all posts
Showing posts with label methods of rca. Show all posts

Monday, October 3, 2016

Analysis of Root Cause Analysis

“To stumble twice against the same stone is a proverbial disgrace.”
Marcus Tullius Cicero

The above statement teaches a very simple thing, that a mistake made more than once is a blunder. Yet we choose to make same mistakes over and over again instead of using a simple and very effective method of RCA. Repetition of the same problem is a very troublesome issue especially in the field of software engineering. In my view RCA is the only technique that can help you to identify the major issues that contribute to the toughest of the problems that you may be facing irrespective of the fact in which field you work may it be engineering, manufacturing or medicine. There is no other tool in my opinion as simple as RCA and effective too at the same time.

The ‘5-WHY’s’ and the ‘Ishikawa Diagram’ are the two most popular techniques to carry out RCA. They have been in usage for more than 25 years now but it was with the popularity of six sigma and lean manufacturing that RCA really came into vogue and got the necessary recognition that such a fine tool deserved. However, even though much has been written and discussed about RCA it is still not used intensively and is a much underutilized tool given its benefits and effectiveness.

The successful implementation of RCA is inhibited due to two reasons. The first one is the lack of organizational support in the form of work process and policies and the second is that individuals are not willing to carry out RCA. The latter is traceable to the former. If the organization does not support the RCA then it will be obviously opposed by the individuals within the organization. Although this may not always be true but the principles and policies of the organization do affect the way individuals may approach RCA. Sometimes the organization may support the RCA but individuals may run away from it due to certain organizational processes and policies. Unawareness in the organization as how to apply RCA strategically along with the lack of work culture that supports the usage of RCA discourages most of the professionals from using RCA. Most of the organizations train their professionals to carry out RCA but they do not really have any policies that will help in implementation of RCA.

Individuals working in the organization would agree that RCA is a great tool and must be used but they really don’t use it. The most of the organizations are task oriented and solving the problem immediately is given more emphasis rather than carrying out the process of RCA which may take more time than the immediate corrective measures. This is the reason why most of the professionals would say that they do not have time for RCA and leave it to be done at some later stage. Hence I will attribute the unwillingness of the individuals to carry out RCA to the organizational work cultures. Sometimes individuals do carry out the RCA in full force but when they report the corrective measures to the management, these measures are either rejected or accepted but not implemented. Such actions of the management discourage the individuals to carry out RCA in future.
There is a big misconception amongst the professionals within the organizations that to implement RCA successfully you need some new tools or different skill set. Once they undergo training for the RCA they are normally disappointed that it was not something radically different and can be easily learnt. They now attribute RCA to common sense but I do not view RCA as common sense. The reason why I cannot attribute RCA to common sense is that if the same problem is given to be analyzed by two different people with notably different ideas, perceptions, backgrounds and experience, they will definitely identify a different root cause for that problem. Hence RCA is not just common sense.

RCA if utilized to its full extent can really do wonders for any type of an organization as it helps in identifying the causes which if removed can permanently prevent the recurrence of the problem. The biggest advantage of RCA is that it really needs no software to do the analysis and reach to root causes. In fact the software’s that are available have the specific categories under which the causes are to be enlisted. I do not consider this to be a valid approach as it would limit the thought process of the individuals. And in some cases it would lead to the conflict as to whether a specific cause should be kept under which category as it may seem valid under more than one category. Some software’s allow categories to be added to the existing ones but using software normally inhibits the thinking process of the individuals carrying out RCA. In my opinion the RCA can yield the best results if carried out in a team. The reason for this is that a single individual may not be able to figure out all the factors that lead to a problem. This would happen because a single individual will have a limited knowledge of his own and may also bring in the bias. Having a team carrying out RCA will bring a greater level of knowledge and experience and the outcome will be more effective. For example if there is a problem in software, the system design analyst will tend to propose solutions based on the causes that may crop up due to design of the software. Similarly the developer will tend to identify the causes associated with the code. Thus having a team will help to identify all the causes and selection of the best cause as the root cause.


Root Cause Analysis is a very useful method to find out the underlying causes for the problems but to make it a success organizational support is very important. The best part of RCA is that it can be applied to almost everything that may be experiencing some problem. My opinion on RCA is that it should be extensively used especially in the field of software engineering. But its use is not limited to software engineering domain only. It can be very much successfully applied to other engineering domains, medical sciences, manufacturing processes, organizational issues and even to our daily life. The combination of “5-WHY’s” and “Ishikawa Diagram” give you a powerful yet easy to use tool for RCA. All that is needed is a pen, sheet of paper and an open mind to start with RCA.

Here are the links to RCA's IntroductionPhases and Techniques

Thursday, September 29, 2016

Techniques (Methods) of RCA: 5-Why's and Ishikawa Diagram

Techniques/Methods used to perform RCA:-

There are many techniques that can be used to carry out RCA but “5-WHY’s” and “Ishikawa Diagram” are the most popular ones and hence I am explaining them in detail in this blog post.


This technique was developed by Sakichi Toyoda, founder of Toyota Industries Co. Ltd. In this technique a series of five questions are asked in order to reach to the root cause. In some cases the questions asked could be more or less than five questions as five questions may not always be sufficient to lead to the root cause. But if the questions asked are proper and within context then in normal circumstances 5-WHY’s will lead to the root cause. In this technique the problem that has to be analyzed is written down and the question asked is generally why it happened. The answer to the problem is written down and this process is iterated until the root cause is reached.

This technique is very basic in nature and takes a fairly small amount of time and does not require any software or other materials. All you need is a paper and a pen and you can start as there is no analysis of statistics involved. However only one root cause can be found for the problem being analyzed using this technique. Also if two different people are analyzing the same problem using this technique they will point out different root causes. If however the answer to the “WHY” question being asked currently can be verified on the spot of the occurrence of the problem the issues discussed above can be avoided.

An example on how find the root causes by using 5-WHY’s:-
1    1. Why is your computer not operating?
          - Because the operating system crashed.
2    2. Why did it crash?
          -  Because it was infected by a virus.
3    3. Why was it infected by virus?
          - Because I had not installed an anti-virus software on my computer.

Ishikawa Diagram:-

Ishikawa Diagram is one of the oldest techniques used for RCA and was developed by Karou Ishikawa who used it in the 1960’s. It is also known as cause and effect analysis or fishbone diagram. The reason why it is known as fishbone diagram is because its shape resembles the bone of a fish.

 In this technique all the possible causes and their effects for the problem are listed down. An Ishikawa diagram generates and sorts hypotheses about possible causes of problems within a process by asking participants to list all of the possible causes and effects for the identified problem. The links between the events and their causes which could be actual or potential are shown by this technique in the Ishikawa diagramThus a very large amount of information can be represented using this technique. This information is then used to generate ideas as to why the problem (or cause) occurred and what could be the possible effects of that problem (or cause).


                      Fig. A sample template showing the layout of the “fishbone diagram”.

A template should be constructed as shown in the figure. The effect (or problem) should be written in the box on the right hand side as shown in the Fig. The effect should reflect what is happening and must be defined without any ambiguity. The categories are identified and written on the top of the slanting lines that come out from the horizontal line. Many authors tend to give a specific list of categories in which the causes should fall but in my opinion the categories of causes should depend on the type of problem. Hence you can use those categories that suit your problem the best. Once the categories have been identified, the underlying causes in each category are found out and written in the form of sub branches to the categories as shown in the Fig. After this step, questions in the form of ‘why this happened’ are asked to identify why that cause took place. The answer to these questions forms the sub branches for the cause as shown in Fig. There is no restriction as to how many questions should be asked as it should be continued until almost all the aspects as to why the cause took place have been covered. Once all the causes have been discussed and dissected in detail, the root cause can be traced. The best method to do this is to establish the chain of events in such a way that the answer to the ‘why’ question traces back to the effect block.

The biggest advantage of Ishikawa diagram is that it gives all the causes that may have an effect on the system. This is useful as it can lead to the discovery of more than one root cause. It is a very useful technique for RCA when using a team to analyze the problem as it keeps everyone involved. The ideas are arranged in logical groups and one cause leads to another. Once the causes have been listed various countermeasures are applied to check whether they solve the problem. This can lead to the wastage of time, money and effort. This technique only gives what could be the root cause to a problem. In order to establish a root cause data must be collected and used to verify each cause which may be thought of as a root cause. As the diagram tends to be complex and large, if it is not drawn appropriately it may result in overlooking of important causes which must be avoided. The best part is that it is easy to carry out and to get started you don’t need any software or other tools.

Besides ‘5-WHY’s’ and ‘Ishikawa Diagram’ there are number of other methods devised over the years. All of them have their particular importance for specific fields in which they can be employed. Cause and Effect Analysis (Tree Diagram), Failure Mode and Effects Analysis, Pareto Analysis, Fault Tree Analysis, Bayesian Inference, Cause Mapping, Barrier Analysis, Change Analysis, Causal Factor Tree and Analysis, Taproot, Apollo Root Cause Analysis (ARCA), RPR Problem Diagnosis, Kepner-Tregoe Problem Solving and Decision Making, Management Oversight and Risk Tree (MORT) Analysis are the other RCA techniques that are widely used.

Next and the final post for RCA on my blog will be regarding an indepth analysis of root cause analysis.