Six Sigma – Root Cause Analysis Techniques

Many techniques available in conducting Root Cause Analysis, each technique has its own advantages and suitable for a particular situation. Common, widely accepted and simple to use techniques includes

·        Cause & Effect diagram

·        5-Why Analysis

·        Brainstorming

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Cause & Effect Diagram: Also called as Fishbone diagram. This is a tool for identifying all the causes of an effect. The effect being examined is the problem/opportunity that has to be eliminated. C&E Diagram is a graphical representation of the causes and effect. Use this technique for

·        Multiple causes has to be grouped logically

·        Understand width and depth of the causes

·        Problem is repetitive

Steps:

·        Write down the effect to be investigated and draw the backbone arrow (as below)

Note: KB Article – Knowledge Base Article has to be selected by the engineer to resolve an issue reported by the customer. Selecting of wrong article either delays the resolution or unnecessary escalation to a next level as the issue is unresolved by the engineer. 

·     Brainstorm with the identified people considering all the broad areas/ groupings of the potential causes of the effect “Classified KB article is incorrect”. Rule of thumb consider the generic 4 categories i.e., Man, Method, Material and Environment. You can define your own categories and may use affinity diagram to group the cause.

·        Group the causes identified during the brainstorming into logical groupings to represent the Cause & Effect relationship.

·        Drill Down all the causes for further reasons and goon extending the branches till the root cause is identified (May use 5-Why technique as required)

Five – Why Analysis: 5-Why is a problem solving technique that allows us to reach the root cause by repeatedly asking the questions. Even though this technique is called “5-Why” we may reach the root cause with fewer or more than five questions. Use this technique

·        Repetitive issue without any supporting data

·        Simple and low risk problems that does not require significant analysis

·        Problem is very specific to a process/ system (Not spread to multiple processes)

Steps:

·        Define the problem

·        Gather the team and confirm the problem

·        Ask the first Question Why? Record all the answers on a whiteboard or flipchart

·        Ask few more successive “Why” until we reach no further causes

·        Confirm the root cause and proceed for next set of actions

Example: Customer complaints on the delay in Pizza delivery

·        Why there is a delay in the Pizza delivery?

o   Delivery boy not reached on time

·        Why the delivery boy not reached on time?

o   He could not find the address

·        Why he could not find the address?

o   Address given to him is incorrect

·        Why the address is incorrect?

o   Address is not available in the records

·        Why the address is not available in the records?

o   Customer is new, manually note down the address

·        Why the address is incorrect?

o   Incorrectly noted while taking orders

Solution: Incase of the first time users, confirm the address once again and provide the telephone numbers to the delivery boy to reach out to the customer in case of any issues.

Brainstorming: One of the very widely used and easy to use techniques for analyzing the problem to reach the root causes. Brainstorming generates ideas and later evaluated to finalize and confirm the causes.  

Steps:

·        Establish a clear objective, Re-phrase for confirmation

·        Create a list of questions

·        cover all potential causes in the following four areas People, Process, Environment, Tools

·        Document all the findings and agree on the same