Six Sigma – Root Cause Analysis (RCA)

Introduction: Beneath every problem there is an underlying cause but we need to identify the root cause to prevent the recurrence. Many times the actions taken to address the issue reoccur again in the same place or in a different place. This symptom indicates that the root cause is not been identified/addressed. Root Cause Analysis (RCA) is a structured approach for identifying and eliminating the underlying root causes. It may not be feasible or necessary to conduct RCA for all the issues as it involves time and effort. RCA is an analytical tool to perform a comprehensive, system-based review of critical incidents. Primary objectives of RCA includes

·        The primary aim is to identify the root cause(s) and prevent that problem from ever recurring

·        Systematic way of approaching and resolving the problem

·        Prevent the recurrence at lowest cost in the simplest way

Steps:  

1. Define the problem
2. Gather the information
3. Plan for Root Cause Analysis
4. Conduct RCA
5. Develop the solutions and action plans
6. Manage the Action items

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 

Leadership - Managers Vs Leaders

Six Sigma – Improvement Approaches

In Six Sigma program there are multiple approaches that can be applied or used depending on the opportunity/problem being addressed. Below approached are majorly used either in solo or in combination in the six sigma program.

·        Lean

·        PDCA

·        Six Sigma – DMAC

·        Six Sigma – DFSS

Below table shows the criteria that can be used as guidelines for selecting the approach

Below table shows the high level details about the approaches.

Differences between Lean and Six Sigma: There are many similarities between Lean and Six Sigma with respect to the approach/objectives. Below tables shows few differences between the two approaches and suggested technique is a blend of both again depending on the problem/opportunity in hand.

Leadership – People

A candidate for a news broadcasters post was rejected because of his voice. He was also told that with his obnoxiously long name, he would never be famous.

-        Amitabh Bachchan.

A small boy – the fifth amongst several siblings of a poor father, was selling newspapers in a small village to earn his living. He was not exceptionally smart at school but was fascinated by religion and rockets. The first rocket he build crashed. A missile that he built crashed multiple times and he was made a butt of ridicule. He is the person to have scripted the space odyssey of India single-handedly.

-        Dr. APJ Abdul Kalam.

In 1962, four nervous young musicians played their first record audition for the executives of the Decca recording Company. The executives were not impressed. While turning down this group of musicians, one executive said, “We don’t like their sound. Groups of guitars are on the way out.”

                                                                                                     -  The group was called The Beatles

In 1944, Emmeline Snively, director of the Blue Book Modelling Agency told modelling hopeful Normal Jean Baker, “You’d better learn secretarial work or else get married.”

-        Marilyn Monroe

In 1954m Jimmy Denny, manager of the Grand Ole Opry fired a singer after one performance. He told him, “You aren’t going’ nowhere…son. You ought to go back to driving’ a truck.”

-        Elvis Presley

When a gentleman invented a communications machine in 1876, it did not ring off the hook with calls from potential backers. After making a demonstration call, President Rutherford Hayes said, “That’s an amazing invention, but who would over want to see one of them?”

-        Alexander Graham Bell

In the 1940s another young inventor named Chester Carlson took his idea to 20 corporations, including some of the biggest in the country. They all turned him down. In 1947, after seven years of rejections! He finally got a tiny company in New York, the Halod Company, to purchase the rights to his invention an electrostatic paper-copying process. Haloid became Xerox Corporation.

-        Chester Carlson

A 4 year old girl- the 20^th of 22 children, contracted double pneumonia and scarlet fever at a very early age, which paralyzed her left leg. Thereafter at 9 y ears of age she removed her leg braces and started walking without them. At 13 she decided to become a runner but kept failing miserably in all races that she entered in. She kept trying inspite of several detractor and finally started winning every race she entered.

-        Wilma Rudolph, winner of 3 Olympic gold medals

A school teacher scolded a boy for not paying attention to his mathematics and for not being able to solve simple problems. She told him that he would not become anybody in life. His mother, however believed in him and coached him in maths.

-        Albert Einstein.

Six Thinking Hats

'Six Thinking Hats' a tool created by Edward de Bono is an important and powerful technique used for decision making. This tool helps in thinking outside the normal styles and guides you to consider the rounded view of a situation. This is a very simple technique and easy to use, effective parallel thinking process that increased the productivity.  This tool, once learned can be applied immediately!

This technique is build based on the principle of parallel thinking which means at any moment everyone is looking in the same direction and the direction is been changed until we reach the decision.

Six Thinking Hats technique can be used in meetings targeted for a critical decision making. Each hat is a different style of thinking as explained below:

White Hat

·     Neutral and objective, Focus on the available data

·     Learn from the information that is available

·     Analyze past trends from historical data

·     Exclude opinions, feelings etc.,

·     Questions

o   What do we know? What is missing? What would we want to know?

·     Facts can be of two levels

o   Believed facts, Verified facts

Red Hat:

·     Emotional and angry

·     Look at problems using intuition, gut feelings

·     Understand the responses of people

·     Don’t expect any logical reasoning’s for the feelings and justifications

Black Hat:

·     Consider all the negative points

·     Be cautious and defensive

·     Make your plans 'tougher' and more resilient

·     Spot flaws and risks before the actions

·     Logically negative – Why this won’t work?

Yellow Hat:

·     Best case scenario

·     Benefits

·     Think positively

·     Have an optimistic viewpoint to see the benefits

Green Hat:

·     New ideas, concepts, creative solution

·     Alternative solutions

·     Growth and fertility

·     Stands for creativity

·     No criticism of ideas

Blue Hat:

·     Cool and sky above

·     Control the decision making process

·     Move Green hat in case we are running out of ideas

·     Move to black hat in case of contingency

·     Organizes the thinking

How to use the hats:

·     Use any hat as needed and it can be more than once

·     Sequence can be decided before the meeting or it can be evolved as we progress

·     Not necessary to use every hat for each decision making situation

·     Keep the time under each hat as short

·     Ensure discipline from each person and can have ground rules set before the meeting

·     This tool can be used by individuals and groups

·     Most used scenario - Open with a blue hat and end with blue hat

o   Open with blue hat

§  Why are we here? What are we thinking? What is the objective

§  Definition of the problem/situation

§  End state, Background or context

§  Plan the hats sequence

o   End with blue hat

§  What did we achieved

§  Outcome/Conclusion

§  Solution/Next steps

Summary:

Blue – Control & Organization of thinking process

White – Objective facts and numbers

Red – Emotions and feelings

Yellow – Hope, Positive

Green – Creative and lateral

Black – Careful and cautious

Analytics – Lead Time Prediction

Below approach can be used to predict the lead time of completing a project considering the variation and cycle time distribution from the past data. The results are interpreted considering the probability of interest.

Steps to predict the Lead Time:

• Collect the data from past related to cycle time and data may include the sub divisions i.e., cycle time may include the actual cycle time, hold time, cycle time of multiple steps etc.,

o   E.g., Project of setting up a new server may include purchase, installation steps. While gathering the data we can collect the data at the desired level to capture the uncertainty in each steps while predicting.

  

•        Understand the distribution of the data

•     Calculate the Lead cycle time for multiple probabilities considering the distribution data is following. For this example we are considering that the data is following Normal Distribution. We can use Excel Function NORM.INV (probability, mean, standard_dev) to calculate the Lead time (Predicted) for the project considering different probabilities

• Another way of predicting the lead cycle time is through simulation. Assuming normal distribution generate the normal variables

o   Cycle Time : Mean (31) and Standard deviation (17)

o   Hold Time : Mean (23) and Standard deviation (24)

o   Add up to get the Total Cycle time = Cycle Time + Hold Time

• From this you can interpret that 90% probability cycle time = 103 days
• Probability to complete the project in 60 days = 55%