An extension of the topic on identifying root causes using a cause & effect (C&E) diagram that will lead toward building a data collection plan (DCP).

1. Section & Lesson #:
Pre-Requisite Lessons:
Complex Tools + Clear Teaching = Powerful Results
Identify Root Causes – C&E Diagram
Six Sigma-Measure – Lesson 23
An extension of the topic on identifying root causes using a cause & effect
(C&E) diagram that will lead toward building a data collection plan (DCP).
Six Sigma-Measure #22 – Identify Root Causes – DCP Overview
Copyright © 2011-2019 by Matthew J. Hansen. All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted by any means
(electronic, mechanical, photographic, photocopying, recording or otherwise) without prior permission in writing by the author and/or publisher.

2. Why Do We Need This Tool?
o Remember, our goal of building the transfer function (Y = f(X)) begins with the DCP.
• We should already know the Y, so now we need to find the potential X’s for the transfer function.
• The data collection plan (DCP) helps ensure we have enough data measuring the Y and every X.
• Below is the method previously described for helping to build the DCP:
Copyright © 2011-2019 by Matthew J. Hansen. All Rights Reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted by any means (electronic, mechanical, photographic,
photocopying, recording or otherwise) without prior permission in writing by the author and/or publisher.
2
1. Define phase
items plus Y &
defect definitions
2. Validate Y &
defect definition
with Team
3. Identify
potential X’s
4. Narrow
down to most
critical X’s
5. Build a data
collection plan
for critical X’s
INPUT to Meeting PROCESS during Meeting OUTPUT from Meeting
Tools: Cause & Effect (C&E) Diagram (a.k.a.,
Fishbone/Ishikawa diagram) and 5 Whys
Tools: Cause &
Effect (C&E) Matrix
Tools: Sample Size Calculator
& Data Collection Plan

3. C&E Diagram Defined
o What is a Cause & Effect (C&E) Diagram?
• It’s a collaborative tool (a.k.a., Fishbone diagram or Ishikawa diagram) used by a team to help
identify all possible causes for a particular undesirable effect.
o What is the purpose of a C&E Diagram?
• Helps a team focus on a problem’s content and not its history.
• Keeps the team focused on the problem’s causes instead of the symptoms.
• Uses a team’s collective knowledge to build a holistic view and create team consensus of all
possible causes affecting a problem.
o Below is an example of a C&E Diagram built in Minitab:
Copyright © 2011-2019 by Matthew J. Hansen. All Rights Reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted by any means (electronic, mechanical, photographic,
photocopying, recording or otherwise) without prior permission in writing by the author and/or publisher.
3
Customer
waits too
long before
talking to
agent
Materials
Mother Nature
Measurements
Methods
Machines
Manpower
Low Staffing Lev els
Slow sy stem
Processes require
putting customer on
hold to w rap up last
call
A gents aren't
measured on A v g
Speed to A nsw er
C all reasons change
throughout day
(longer calls)
C all v olume changes
throughout day
(affects staffing)
Cause-and-Effect Diagram

4. Building a C&E Diagram
o How do you build the C&E Diagram?
• Gather the team to build it together.
 The C&E Diagram should be a collaborative, team product; it shouldn’t be created by just one person.
 Build the diagram with the team on a dry erase board or flip chart using post-it notes.
– There are many useful tools for building the diagram (e.g., Minitab, Excel, Visio, etc.); however, when working with a
team, it can be more effective to build it manually first using post-it notes and using software later to document it.
• Define the “Effect”.
 This will most likely be the defects that were defined
(or somehow tied to the problem statement).
– If you have multiple defects defined, then each unique
defect can be an “effect” for multiple C&E diagrams.
• Draw and label the diagram’s “bones”.
 Below are common sources of variation that can be
a suggested list of labels for each “bone”:
– Manpower – Personnel issues like turnover, training, etc.
– Machine - Issues related to equipment, hard/software, etc.
– Method - Issues related to policies, SOPs, regulations, etc.
– Measurement - Issues related to how things are measured
like standards, performance, goals, etc.
– Materials - Issues related to documentation, forms, etc.
– Mother Nature - Issues related to outside influences like the economy, customers, vendors, etc.
 These labels can be modified and should be limited to just 4 to 6 unique labels.
– The labels help categorize possible causes so it’s important that they are unique and relevant to the identified “effect”.
• Brainstorm potential causes for each of the “bone” categories.
 Write on a post-it note a potential cause and stick it to each category. Move them around as necessary.
• Identify sub-causes by drilling more deeply into each cause by asking “Why does this happen?”
 Notate each sub-cause as another “bone” extending off the main “bones”.
Copyright © 2011-2019 by Matthew J. Hansen. All Rights Reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted by any means (electronic, mechanical, photographic,
photocopying, recording or otherwise) without prior permission in writing by the author and/or publisher.
4
Cause & Effect Diagram
Materials Methods Manpower
Mother
Nature
Measurement
s
Machines

5. Documenting a C&E Diagram
o How do you document the C&E Diagram?
• After the team manually builds the C&E diagram, it should be documented using various software
tools to make it easily accessible and to embed it into the project storyboard.
• Below are the instructions for building the diagram into Minitab:
 Begin by typing the identified causes into different columns in Minitab’s worksheet.
 In Minitab go to Stat > Quality Tools > Cause and Effect…
 Update the “Label” section to reflect the “bone” labels used in the diagram.
 For the “Causes”, assign the column title respective to the label you noted.
– If you have sub-causes, change the “In Column” drop-down to “Constant” to reflect the name of the new bone extension.
– Then click the “Sub…”button and assign the column title respective to the newly created label.
 Type in the “Effect”.
 Add a new title as needed,
otherwise Minitab will entitle it
“Cause and Effect Diagram”.
 The dialog example (at right) is
what was used to create the
previously shown C&E diagram.
Copyright © 2011-2019 by Matthew J. Hansen. All Rights Reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted by any means (electronic, mechanical, photographic,
photocopying, recording or otherwise) without prior permission in writing by the author and/or publisher.
5

6. Practical Application
o Identify a prior project or initiative you worked in your organization.
• Try building a C&E Diagram for that project or initiative by answering the following:
 What was used as the critical metric (project Y)?
 How would you define a defect?
– This would be the ultimate “effect” used in the C&E Diagram.
 Review each source of variation listed below and notate any related causes leading to the effect.
– Manpower
– Machine
– Method
– Measurement
– Materials
– Mother Nature
 Notate any additional sub-causes that also eventually lead to the ultimate effect.
• Try building the C&E Diagram in an online tool like Minitab, Visio, PowerPoint, etc.
Copyright © 2011-2019 by Matthew J. Hansen. All Rights Reserved. No part of this publication may be
reproduced, stored in a retrieval system, or transmitted by any means (electronic, mechanical, photographic,
photocopying, recording or otherwise) without prior permission in writing by the author and/or publisher.
6