Root Cause Analysis Methodology & Tools By Gustavo Diaz, ASQ CSSBB

Root Cause Analysis 

Teams & Problem Definition  



Team Development & Classification Problem Definition

RCA DMAIC 

Define 



Measure 



Evaluation matrices, FMEA, Pugh Matrix, DOE, Force Field Analysis (Barrier Analysis)

Implement 



Check sheets, Pareto analysis, Scatter diagrams, Run charts, Tree diagrams, Flow charts, Process mapping

Analyze 



Statement of Opportunity, Problem definition, Brainstorming, Affinity diagrams

Gantt Charts, Action Plans (definition of components), Contingency Plans, Monitoring

Sustain 

SPC charts, Check sheets, Contingency plans, RACI.

Copyright 2015-2016. All rights reserved.

2016

2

Root Cause Analysis - Environment Forming

Storming

Adjourning

Team

RCA Methodology Performing

Norming

Define

Problem

Statem Proble m ent of Opport State ment unity

Measure

Charte r

Check sheets Pareto Analysi s Scatter Diagra ms

Tree Diagra ms Flow charts Proces s maps

Analyze

FMEA Pugh Matrix

Force Field Analysi s DOE

Execute

Gantt charts Action Plans Contin gency Plans

Monito ring

Comm unicati on

Sustain

SPC

RACI

Effects Failure Modes Causes • Potential Causes

Critical Causes

Copyright 2015-2016. All rights reserved.

2016

3

Root Cause Analysis – Problem Solving Tools Steps

Tools

Notes

Problem Definition

Brainstorming Buzz Groups Nominal Groups Delphi Methods Focus Groups

Root Cause Analysis: Likelihood of occurrence vs. severity of Incident.

Problem Statement

Affinity diagrams Fault trees Critical to Quality (CTQs) Kano Model SWOT analysis

Creation of a Problem charter. Definition of a “decision criteria” for alternative solutions selection.

Measure

Check sheets Pareto analysis Scatter diagram Run charts Tree decomposition diagrams Flow charts Process mapping

These techniques will include their definitions, as well as hands-on on the techniques, using cases or Client specifics.

Analyze

Ishikawa diagram 5 Whys Evaluation matrices FMEA Pugh Matrix DOE Force Field Analysis (Barrier Analysis)

Execute

Gantt Charts Action Plans (definition of components) Contingency Plans Monitoring

Sustain Solution Copyright 2015-2016. All rights reserved.

These techniques will include their definitions, as well as hands-on on the techniques, using cases or Client specifics.

These techniques will include their definitions, as well as hands-on on the techniques, using cases or Client specifics.

SPC charts Check sheets RACI 2016

4

Root Cause Analysis - Introduction

Root-Cause Analysis (RCA) Problem Definition

Statement of opportunity Problem statement Brainstorming Buzz groups CTQs Affinity diagrams

Copyright 2015-2016. All rights reserved.

Measure

Check sheets Pareto charts XY diagrams Run charts

Analyze

Ishikawa diagram 5 Whys Delphi methods Nominal groups Tree decomposition Flow charts Process maps FMEA Pugh matrix

Execute

Force field analysis Gantt charts Action plans

Sustain

Check sheets SPC Contingency plans RACI

2016

5

Root Cause Analysis - Introduction 



What is a (business) Problem? 

A perceived gap between the existing state and a desired state; or a deviation from a norm, standard, or status quo.



Although many problems turn out to have several solutions (means to close the gap or correct the deviation), difficulties arise where such ways are either not obvious or are not immediately available.

What is Problem-Solving? 

Problem solving consists of using generic or ad hoc methods, in an orderly manner, for finding “best” solutions to problems.



Problem-solving is a mental process that involves discovering, gathering, and analyzing facts (data) to solve problems. The ultimate goal of problem-solving is to overcome obstacles and find a solution that “best” resolves the issue.

Copyright 2015-2016. All rights reserved.

2016

6

Root Cause Analysis - Introduction 

Problem Solving Methodologies There are several problem solving methodologies 1.

Problem-Definition Process (Sep-2012, Harvard Business Review)

2.

Plan-Do-Check-Act (PDCA Cycle, or Deming Cycle)

3.

Soft Systems Methodology (SSM)

4.

(Global) 8D Problem Solving Process (Ford Motor Co., 1982)

5.

The Cynefin Framework (Davis Snowden, 1999)

6.

Appreciative Inquiry (Case Western Reserve, 1980)

7.

The Simplex Process (Min Basadur, 1995)

8.

The Straw-man Concept

9.

Hurson’s Productive Thinking Model (2007)

10. Action 11. The

Learning Sets (Reginald Revans, 1983)

FOCUS Model (TQM, Healthcare)

Copyright 2015-2016. All rights reserved.

2016

7

Root Cause Analysis - Introduction 

Proposed Methodology 1. Based upon the strong believe that customer comes first, and process are geared to satisfy 100% (6σ) client expectations and requirements. 2. Based upon Six Sigma DMAIC  Define

a Problem

 Measure

the Problem

 Analyze

the Problem

 Improve

/ Implement the Solution(s)

 Sustain

the Solution(s)

3. Based upon a strong team commitment and culture

4. Strong top-down managerial support Copyright 2015-2016. All rights reserved.

2016

8

Root Cause Analysis - Environment Forming

Storming

Adjourning

Team

RCA Methodology Performing

Norming

Define

Problem

Proble m Statem ent

Charter

Measure

Check sheets Pareto Analysis Scatter Diagra ms

Tree Diagra ms Flow charts Process maps

Analyze

FMEA Pugh Matrix

Force Field Analysis DOE

Execute

Gantt charts Action Plans Conting ency Plans

Monitor ing

Commu nicatio n

Sustain

SPC

RACI

Effects Failure Modes Causes • Potential Causes

Critical Causes

Copyright 2015-2016. All rights reserved.

2016

9

Root Cause Analysis – The Team 

What is a Team? 

A group of people with a full set of complementary skills required to complete a task, job, project, or solve a problem.



Team characteristics 1. operate with a high degree of interdependence, 2. share authority and responsibility for self-management (empowered teams), 3. are accountable for the collective performance, and 4. work toward a common goal and shared rewards(s).



A team becomes more than just a collection of people when a strong sense of mutual commitment creates synergy, thus generating performance greater than the sum of the performance of its individual members.



The mutual commitment and sense of shared goals happens throughout a series of stages…

Copyright 2015-2016. All rights reserved.

2016

10

Root Cause Analysis – The Team 

Team Formation Stages 



The Forming Storming Norming Performing theory from Dr. B. Tuckman (1965, 1975), is a proven, helpful explanation of team development and behavior.

Developmental progression:  Forming  Storming  Norming  Performing  Adjourning

Copyright 2015-2016. All rights reserved.

2016

11

Root Cause Analysis – The Team Stage

Team Behavior High dependence on leader for guidance and direction.

Forming Individual R & R are unclear.

Processes are often ignored. Members test tolerance of system and leader.

Leader Trait Leader directs

Storming

Team members attempt to establish themselves in relation to other team members and the leader. Clarity of purpose increases, but plenty of uncertainties persist. Cliques and factions form and there may be power struggles.

Leaders coaches

Norming

Agreement and consensus largely forms among the team. Roles and responsibilities are clear and accepted. Big decisions are made by group agreement. Commitment and unity is strong. General respect for the leader and some of leadership is more shared by the team.

Leader facilitates and enables

Performing

The team has a shared vision and is able to stand on its own feet with no interference or participation from the leader. Team has a high degree of autonomy. Able to work towards achieving the goal, and also to attend to relationship, style and process issues along the way. Team members look after each other. Team members might ask for assistance from the leader with personal and interpersonal development.

Leader delegates and oversees

Adjourning

Tuckman's fifth stage is the break-up of the group, hopefully when the task is completed successfully. From an organizational perspective, recognition of, and sensitivity to people's vulnerabilities is helpful, particularly if members of the group have been closely bonded and feel a sense of insecurity or threat from this change. Feelings of insecurity would be natural for people with high 'steadiness' attributes and with strong routine and empathy style.

Copyright 2015-2016. All rights reserved.

Leader consoles and advises 2016

12

Root Cause Analysis – Problem Definition

Root-Cause Analysis (RCA) Problem Definition

Statement of opportunity Problem statement Brainstorming Buzz groups CTQs Affinity diagrams

Copyright 2015-2016. All rights reserved.

Measure

Check sheets Pareto charts XY diagrams Run charts

Analyze

Ishikawa diagram 5 Whys Delphi methods Nominal groups Tree decomposition Flow charts Process maps FMEA Pugh matrix

Execute

Force field analysis Gantt charts Action plans

Sustain

Check sheets SPC Contingency plans RACI

2016

13

Root Cause Analysis – Problem Definition 

What is it? 

Root Cause Analysis (RCA) is a problem solving method used for identifying the root causes of faults or problems.



A critical factor is considered a root cause if removing it from the problem-fault-sequence, prevents the final undesirable event from occurring or recurring.



A causal factor is one that affects an event's outcome, but is not a root cause. Though removing a causal factor can benefit an outcome, but it does not prevent its recurrence within certainty.



RCA is applied to identify and correct the root causes of events. Focusing corrective actions on root causes has the goal of entirely preventing problem recurrence.

Copyright 2015-2016. All rights reserved.

2016

14

Root Cause Analysis – Problem Definition 

Where do we start? 

Statement of Opportunity – general description of the symptoms or the “pain” in the process, or the “pain” caused by the problem.



Usually starts with the sentence “ There is an opportunity to…” , written in noun-verb structure, with an active verb (like eliminate, reduce, minimize, decrease, etc.) It should include the benefits to the customer, and the risk taken by the organization by not solving such “pain”.



Supported with some numbers and more detail once data have been obtained. See Problem Statement next…

Copyright 2015-2016. All rights reserved.

2016

15

Root Cause Analysis – Problem Definition 

Statement of Opportunity – Poor Examples 

Poor Statement of Opportunity 1A: Inventory levels are too high and must be reduced.



Poor Statement of Opportunity 1B: Having too few forklifts is making inventory levels too high.



Poor Statement of Opportunity 1C: Human resources is taking too long to fill personnel requests.



Poor Statement of Opportunity 1D: Our admission office has a problem with the number of insurance claim forms submitted with errors to the insurance company.

Copyright 2015-2016. All rights reserved.

2016

16

Root Cause Analysis – Problem Definition 

Statement of Opportunity – Better Examples 

Good Statement of Opportunity 2A: Inventory levels at the West Metro inventory storage process in Scottsdale are consuming space, taking up asset management time, and creating cash flow issues. These high levels are causing obsolescence affecting customer expiration dates, and causing returns.



Good Statement of Opportunity 2B: Recruiting time for software engineers for the flight systems design department in San Jose is taking long time. This delay is adding costs in overtime, contractor labor, and rework costs; and jeopardizing “go live” deadlines.



Good Statement of Opportunity 2C: Insurance claim forms originating at the Fremont North Memorial emergency department are causing a loss of revenue, excessive rework costs, and delayed payment to the hospital, impacting the cycle time to pay vendors and customers.

Copyright 2015-2016. All rights reserved.

2016

17

Root Cause Analysis – Problem Definition 

Problem Statement – Next step The problem statement serves several purposes in a root cause analysis. First, it clarifies the current situation by specifically identifying the problem, its severity, location, frequency, financial and customer impact (pain).  It also serves as a great communication tool, helping to get buy-in and support from others. When problem statements are well written, people readily grasp and understand what we are trying to accomplish.  A problem statement should be concise and include the following: 

1. A brief description of the problem and the metric used to describe the problem 2. Where the problem is occurring by process name and location 3. The time frame over which the problem has been occurring 4. The size or magnitude of the problem 5. Customer impact. Copyright 2015-2016. All rights reserved.

2016

18

Root Cause Analysis – Problem Definition 

Problem Statements – Good Examples 

Problem Statement 3A: Inventory levels at the West Metro inventory

storage process in Scottsdale are consuming space, taking up asset management time, and creating cash flow issues. Inventory levels are averaging 31.2 days, with a high of 45 days. These levels have exceeded the target of 25 days 95 percent of the time since January 2012. $250,000 could be saved per year if inventories were at the targeted level. 

Problem Statement 3B: Insurance claim forms originating at the Fremont

North Memorial emergency department are causing a loss of revenue, excessive rework costs, and delayed payment to the hospital. Forty-five percent of the claim forms have errors, with an average of 2.3 defects per form. This problem has existed since claims processing was moved to Kansas City in March 2012. Billings could increase by $3.5 million per month, rework cost could be reduced by 50 percent, and an additional 1.3 percent of revenue could be recovered if errors were occurring less than 5 percent of the time. Achieving this level of performance would increase profits by $395,000 per year.

Copyright 2015-2016. All rights reserved.

2016

19

Root Cause Analysis – Problem Definition 

Techniques to aid with the Problem definition… 

Affinity diagrams



Brainstorming



Buzz Groups



Focus Groups



Nominal Groups



Mind Mapping

Copyright 2015-2016. All rights reserved.

2016

20

Root Cause Analysis – Problem Definition  Tools: Brainstorming  Brainstorming is a problem definition / solving approach designed to

help a team clearly define a problem, or generate several creative solutions to a problem. 

It was first developed by Alex Osborn, an advertising executive who felt the need for a problem solving technique that, instead of evaluating and criticizing ideas, would focus on developing imaginative and innovative solutions.

 Brainstorming combines a relaxed, informal approach to problem

solving with lateral thinking. It encourages people to come up with thoughts and ideas that can, at first, seem a bit crazy. Some of these ideas can be crafted into original, creative solutions to a problem, while others can spark even more ideas. This helps to get people unstuck by "jolting" them out of their normal ways of thinking. Copyright 2015-2016. All rights reserved.

2016

21

Root Cause Analysis – Problem Definition

Copyright 2015-2016. All rights reserved.

2016

22

Root Cause Analysis – Problem Definition  Tools:

Brainstorming Characteristics



Procedure designed to release a team's creativity in order to generate multiple imaginative solutions to a problem definition or solution.



Separates the idea-generation from the idea-evaluation process by not allowing any criticism to take place while the team is generating ideas.



May be more productive for each member to brainstorm quietly and then share ideas with the team (brain writing technique). 

Electronic brainstorming puts each member at a computer terminal and their ideas are projected to a screen so no one knows from whom an idea came.

Copyright 2015-2016. All rights reserved.

2016

23

Root Cause Analysis – Problem Definition Tools: Affinity Diagrams

 

The affinity diagram organizes a large number of ideas into their natural, higher-level, relationships and associations. This method taps a team’s creativity and intuition.  It

was created in the 1960s by Japanese anthropologist Jiro Kawakita.



Also called: Affinity chart, K–J method, thematic analysis.



When to Use it? When you are confronted with many facts or ideas in apparent chaos or disarray  When issues seem too large and complex to grasp  When group consensus is necessary  After a brainstorming exercise  When analyzing verbal data, such as survey results. 

Copyright 2014-2015. All rights reserved.

2016

24

Root Cause Analysis – Problem Definition

Copyright 2014-2015. All rights reserved.

2016

25

Root Cause Analysis – Problem Definition 

Tools: Affinity Diagram Procedure 

Record each idea on a separate sticky note or card. The entire team gathers around the notes and participates in the next steps.



It is very important that no one talk during this step. Look for ideas that seem to be related in some way. Place them side by side. Repeat until all notes are grouped. 

It is okay to have “loners” that do not seem to fit a group. It’s all right to move a note someone else has already moved.

 You

can talk now. Team can discuss the shape of the chart, any

surprising patterns, and especially reasons for moving controversial notes. When ideas are grouped, select a heading for each group. Place it at the top of the group.



Combine groups into “super-groups” if appropriate.

Copyright 2014-2015. All rights reserved.

2016

26

Root Cause Analysis – Problem Definition 

Tools: Critical to… CTQs 

CTQ trees (critical-to-quality trees) are the key measurable characteristics of a product or process whose performance standards or specification limits must be met in order to satisfy the customer requirements.



CTQs are used to decompose broad customer requirements impacted by a problem, into more easily quantified elements. CTQ trees are often used as part of RCA methodology to help prioritize such requirements affected by a problem or a defect.



CTQs represent the product or service characteristics as defined by the customer/user. They may include upper and lower specification limits or any other factors. A CTQ must be an actionable, quantitative business specification.

Copyright 2014-2015. All rights reserved.

2016

27

Root Cause Analysis – Problem Definition 

Tools: Critical to… CTQs

Copyright 2014-2015. All rights reserved.

2016

28

Root Cause Analysis - Measure

Root-Cause Analysis (RCA) Problem Definition

Statement of opportunity Problem statement Brainstorming Buzz groups CTQs Affinity diagrams

Measure

Check sheets Pareto charts XY diagrams Run charts

Copyright 2014-2015. All rights reserved.

Analyze

Ishikawa diagram 5 Whys Delphi methods Nominal groups Tree decomposition Flow charts Process maps FMEA Pugh matrix

Execute

Force field analysis Gantt charts Action plans

Sustain

Check sheets SPC Contingency plans RACI

2016

29

Root Cause Analysis – Measure 

Tools: Pareto Analysis 

Pareto Analysis is a quantitative technique in decision-making used for the selection of a limited number of tasks that produce significant overall effect. It uses the Pareto Principle (also known as the 80/20 rule) the idea that by doing 20% of the work you can generate 80% of the benefit of doing the entire job.



Pareto Analysis is a simple technique for prioritizing possible changes by identifying the problems that will be resolved by making these changes. By using this approach, you can prioritize the individual changes that will most improve the situation.



How to use the tool? 

Step 1: Identify and List the Problem



Step 2: Identify the potential Root Causes of the Problem



Step 2: Score the Causes



Step 5: Add up the Scores for each group of Causes



Step 6: Sort and prioritize



Step 7: Take Action

Copyright 2014-2015. All rights reserved.

2016

30

Root Cause Analysis – Measure  Tools:

Pareto Analysis Example

Copyright 2014-2015. All rights reserved.

2016

31

Root Cause Analysis – Measure 

Tools: Scatter Diagrams (XY graphs) 

An XY or scatter plot either shows the relationships among the numeric values in several data series or plots two groups of numbers as a single series of XY coordinates. It can show uneven intervals or clusters of data and is commonly used for business data.



The scatter plot is a type of mathematical diagram using Cartesian coordinates to display values for two variables for a set of data.



A scatter plot can suggest various kinds of correlations between variables with a certain confidence interval. Correlations may be positive (rising), negative (falling), or null (uncorrelated).

Copyright 2014-2015. All rights reserved.

2016

32

Root Cause Analysis – Measure 

Tools: Scatter Diagrams (XY graphs)

Copyright 2014-2015. All rights reserved.

2016

33

Root Cause Analysis – Measure 

Tools: Process Maps Process Mapping, often referred to as Flowcharting, is a graphic representation showing all the inputs, steps, actions, controls and decisions points of a business process.  “As is”: 





“To Be”: 



Teams often start their process improvement efforts by identifying the “actual” path of a process under study that produces a particular product or service. Teams may follow that up with developing the “ideal” path in order to compare it back to the actual in order to identify deviations and then improve them.

Process Maps are great for:  

   

Showing what the current process looks like. Identifying deviations from the norm. Showing relationships between steps or departments involved. Identifying where to collect data and investigate further for improvement opportunities. Use as a training aid (shows how the work should be done). Serving as process documentation and standardization (SOP).

Copyright 2014-2015. All rights reserved.

2016

34

Root Cause Analysis – Measure 

Tools: Process Maps Graphical Tools Inputs

Process

Outputs

Capability

Information

Am I delivering outputs that meet customer expectations?

(Control)

Material (Stability)

Process

Outputs (Attributes)

Labor (Stability)

Tools

• • • •

How good is the measurement system? What are the specs? Are the specs changing? How are we performing?

(Capability)

Control

Stability

Do I know what to do and when to do it?

Do I have input variation that is causing output variation?

• • • •

• • • •

What is the procedure? When do I use it? How do I make decisions? Are my decisions correct?

Copyright 2014-2015. All rights reserved.

Is the process stable? What are my inputs? How do they vary? What is the predictive equation

2016

35

Root Cause Analysis – Measure 

Tools: Process Maps Level -2

Copyright 2014-2015. All rights reserved.

2016

36

Root Cause Analysis - Analyze

Root-Cause Analysis (RCA) Problem Definition

Statement of opportunity Problem statement Brainstorming Buzz groups CTQs Affinity diagrams

Measure

Check sheets Pareto charts XY diagrams Run charts

Copyright 2014-2015. All rights reserved.

Analyze

Execute

Ishikawa diagram 5 Whys Delphi methods Nominal groups Tree decomposition Flow charts Process maps FMEA Pugh matrix

Force field analysis Gantt charts Action plans

Sustain

Check sheets SPC Contingency plans RACI

2016

37

Root Cause Analysis –Analyze  Tools:

Ishikawa Diagram (fish-bone diagram)

Ishikawa diagrams (aka fishbone diagrams, cause-and-effect diagrams) are causal diagrams created by Kaoru Ishikawa (1968) to show the potential causes of a specific event.  Common uses of the Ishikawa diagram are product design and quality defect prevention, to identify potential factors causing an overall effect.  Each cause or reason for imperfection is a source of variation. Causes are usually grouped into major categories to identify these sources of variation. 



These major categories typically include:      

People: Anyone involved with the process. Methods: How the process is performed and the specific requirements for doing it, such as policies, procedures, rules, regulations and laws. Machines: Any equipment, computers, tools, etc. required to do the job. Materials: Raw materials, parts, paper, etc. used to produce the final product. Measurements: Data generated from the process, used to evaluate its quality. Environment: The conditions, such as location, time, temperature, and culture in which the process operates.

Copyright 2014-2015. All rights reserved.

2016

38

Root Cause Analysis –Analyze 

Tools: Ishikawa Diagram (fish-bone diagram)

Copyright 2014-2015. All rights reserved.

2016

39

Root Cause Analysis – Analyze 

Tools: Ishikawa Diagram (fish-bone diagram)

Copyright 2014-2015. All rights reserved.

2016

40

Root Cause Analysis – Analyze 

Tools: 5-Whys? 

By asking "Why?" five times, and in succession, one can delve into a problem deeply enough to understand the ultimate root cause. By the time you get to the 4th or 5th why, you will likely be looking some measurable practice or the lack thereof.



This methodology is closely used with the Cause & Effect (Ishikawa) diagram.



Many times teams will stop once a reason for a problem or a defect has been identified. This reason may not be the root cause.



The purpose of 5-whys analysis is to get the right people in the room discussing all of the potential root causes of a given problem or defect in a process.

Copyright 2014-2015. All rights reserved.

2016

41

Root Cause Analysis – Analyze 

Tools: Failure Mode & Effects Analysis 

Failure Modes and Effects Analysis (FMEA) is a step-by-step approach for identifying all possible failures in a design, a manufacturing or assembly process, or a product or service.



“Failure modes” mean the ways, or modes, in which something might fail. Failures are any errors or defects, especially ones that affect the customer, and can be potential or actual. 

Failures are prioritized according to how serious their consequences are, how frequently they occur and how easily they can be detected. The purpose of the FMEA is to take actions to eliminate or reduce failures, starting with the highest-priority ones.



“Effects analysis” refers to studying the consequences of those failures.



The FMEA also documents current knowledge and actions about the risks of failures, for use in continuous improvement. FMEA may be used during design to prevent failures. Later on, it is used for control, before and during ongoing operation of the process.



The FMEA is used in RCA to locate in a process where the problem causes occur. It may be used during the earliest stages of root causing.

Copyright 2014-2015. All rights reserved.

2016

42

Root Cause Analysis – Analyze 

Tools: Failure Mode & Effects Analysis 

The steps to complete an FMEA are listed below Step Description 1

Review the process map. List the steps and decisions in the FMEA template.

2

Brainstorm potential failure modes for each step in the process, listed in the FMEA.

3

List all potential effects of the failure (from the customer perspective.

4

Assign Severity rankings

5

Assign Occurrence rankings

6

Assign Detection rankings

7

Calculate the RPN for each line

8

Develop Action Plans

9

Take action, i.e. RACI

Copyright 2014-2015. All rights reserved.

2016

43

Root Cause Analysis – Analyze 

Tools: Failure Mode & Effects Analysis Example 

A bank performed a process FMEA on their ATM system. The figure shows part of it—the function “dispense cash” and a few of the failure modes for that function. According to the RPN, “machine jams” and “heavy computer network traffic” are the first and second highest risks.

Copyright 2014-2015. All rights reserved.

2016

44

Root Cause Analysis – Analyze 

Tools: Failure Mode & Effects Analysis 

Calculation Risk Priority Number (RPN)  The

Risk Priority Number, or RPN, is a numeric assessment of risk assigned to a process, or steps in a process.  The team assigns each failure mode numeric values that quantify likelihood of occurrence, likelihood of detection, and severity of impact.  RPN

utilizes three rating scales:

1. Severity (S) - rates the severity of the potential effect of the failure. 2. Occurrence (O) - rates the likelihood that the failure will occur.

3. Detection (D)- rates the likelihood that the problem will be detected before it reaches the end-user/customer. Copyright 2014-2015. All rights reserved.

2016

45

Root Cause Analysis – Analyze 

Tools: Failure Mode & Effects Analysis 

Risk Priority Number (RPN) Guidelines

Copyright 2014-2015. All rights reserved.

2016

46

Root Cause Analysis – Analyze 

Tools: Design of Experiments 

Design of experiments (DOE) is a statistical systematic method to determine the relationship between factors affecting a process and the output of that process.



It is used to find cause-and-effect relationships. This information is needed to manage process inputs in order to optimize the output.



A strategically planned and executed experiment may provide a great deal of information about the effect on a response variable due to one or more factors that may interact.



Many experiments involve holding certain factors constant and altering the levels of another variable. This One–Factor–at–a–Time (or OFAT) approach to process knowledge is, however, inefficient when compared with changing factor levels simultaneously to determine interactions.

Copyright 2014-2015. All rights reserved.

2016

47

Root Cause Analysis – Analyze 

Tools: Design of Experiments 

The most commonly used terms in the DOE methodology include: controllable and uncontrollable input factors, responses, hypothesis testing, blocking, replication and interaction. 

Hypothesis testing helps determine the significant factors using statistical methods. There are two possibilities in a hypothesis statement: the null and the alternative. The null hypothesis is valid if the status quo is true. The alternative hypothesis is true if the status quo is not valid. Testing is done at a level of significance, which is based on a probability.



Blocking and replication: Blocking is an experimental technique to avoid any unwanted variations in the input or experimental process. Practitioners also replicate experiments, performing the same combination run more than once, in order to get an estimate for the amount of random error that could be part of the process.



Interaction: When an experiment has three or more variables, an interaction is a situation in which the simultaneous influence of two variables on a third is not additive.

Copyright 2014-2015. All rights reserved.

2016

48

Root Cause Analysis - Execute

Root-Cause Analysis (RCA) Problem Definition

Statement of opportunity Problem statement Brainstorming Buzz groups CTQs Affinity diagrams

Measure

Check sheets Pareto charts XY diagrams Run charts

Copyright 2014-2015. All rights reserved.

Analyze

Ishikawa diagram 5 Whys Delphi methods Nominal groups Tree decomposition Flow charts Process maps FMEA Pugh matrix

Execute

Force field analysis Gantt charts Action plans

Sustain

Check sheets SPC Contingency plans RACI

2016

49

Root Cause Analysis – Execute 

Tools: Gantt Charts 

A Gantt chart is a horizontal bar chart developed as a production control tool in 1917 by Henry L. Gantt, an American engineer and social scientist.



A Gantt chart provides a graphical illustration of a schedule that helps to plan, coordinate, and track specific tasks in a project.



Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project. Terminal elements and summary elements comprise the work breakdown structure of the project. 

Modern Gantt charts also show the dependency (i.e., precedence network) relationships between activities.

Copyright 2014-2015. All rights reserved.

2016

50

Root Cause Analysis – Execute 

Tools: Gantt Charts

Copyright 2014-2015. All rights reserved.

2016

51

Root Cause Analysis – Execute 

Tools: Action Plans (component definition) 

Action planning is a process which will help you to focus your ideas and to decide what steps you need to take to implement the solution(s) to a particular problem that you may have. It is a statement of what you want to achieve over a given period of time.



An action plan is a way to make sure the problem at hand is solved, and organization's strategy is made concrete. It describes the way your team will leverage the corrective actions to solve the problem.



Each action step or change to be sought should include the following information: 1. 2. 3. 4.

What actions or changes will occur? Who will carry out these changes? By when they will take place, and for how long? What resources (i.e., money, staff) are needed to carry out these changes? 5. Communication (who should know what?)

Copyright 2014-2015. All rights reserved.

2016

52

Root Cause Analysis – Execute 

Tools: Action Plans (component definition) 

3C’s Criteria to measure a good action plan: 

Complete? Does it list all the action steps or changes to be sought in all relevant parts involved in the corrective actions (e.g., operators, business, managers)?



Clear? Is it apparent who will do what by when?



Current? Does the action plan reflect the current work? Does it anticipate newly emerging opportunities and barriers?

Copyright 2014-2015. All rights reserved.

2016

53

Root Cause Analysis - Sustain

Root-Cause Analysis (RCA) Problem Definition

Statement of opportunity Problem statement Brainstorming Buzz groups CTQs Affinity diagrams

Measure

Check sheets Pareto charts XY diagrams Run charts

Copyright 2014-2015. All rights reserved.

Analyze

Ishikawa diagram 5 Whys Delphi methods Nominal groups Tree decomposition Flow charts Process maps FMEA Pugh matrix

Execute

Force field analysis Gantt charts Action plans

Sustain

Check sheets SPC Contingency plans RACI

2016

54

Root Cause Analysis – Sustain 

Tools: SPC Charts 

Control charts are used to monitor quality and process stability in manufacturing and service processes.



Control charts are graphs used to study how a process changes over time. Data are plotted in time order.



A control chart always has a central line for the average, an upper line for the upper control limit and a lower line for the lower control limit. These lines are determined from historical data.



Depending on the number of process characteristics to be monitored, there are two basic types of control charts. 

The first, referred to as a univariate control chart, is a graphical display (chart) of one process characteristic.



The second, referred to as a multivariate control chart, is a graphical display of a statistic that summarizes or represents more than one quality characteristic.

Copyright 2014-2015. All rights reserved.

2016

55

Root Cause Analysis – Sustain 

What SPC Charts to use?

Process With Continuous Data Charts every data observation Charts a small group of data (between 2-10 observations in one instance/batch/job run)

Charts a larger group of data (more than 11 observations in one instance/batch/job run)

XmR (I&MR) X-bar & R X-bar & s

Process With Discrete Data (Attributes) Counts the number of defects, equal sample size

c-Chart

Counts the number of defects, variable sample size

u-Chart

Charts the proportion of defectives, variable sample size

p-Chart

Charts the number of defective units, equal sample size

np-Chart

Copyright 2014-2015. All rights reserved.

2016

56

Root Cause Analysis – Sustain 

SPC Charts – I&MR Charts 



An I & MR, or Individual & Moving Range Chart, is a graphical tool that displays process variation over time for individual measures (observations) of the process.  It signals when a process may be going out of control and shows where to look for sources of variation. I & MRs are used:  To observe every data point in the process. 



Because our data is continuous and our subgroup size is one.

The Individual (I) Chart plots each measurement (sometimes called an observation) as a separate data point. Each data point stands on its own and there is no rational subgrouping and the subgroup size of 1.

Copyright 2014-2015. All rights reserved.

2016

57

Root Cause Analysis – Sustain SPC Charts – I&MR Charts Part #

Diameter (mm)

1

5.77

2

4.57

3

5.79

4

6.21

5

5.32

6

4.24

7

4.65

8

5.20

9

5.10

10

6.07

11

5.82

12

4.78

13

5.33

14

5.67

15

4.79

16

4.29

2.50

17

6.01

2.00

18

5.23

19

5.78

20

4.56

21

4.98

22

5.27

23

5.80

24

5.21

25

5.67

26

4.88

27

5.10

28

5.92

29

5.11

30

4.93

X Diameter (mm) Diameter (mm)

7.80 6.80 5.80

UCL

7.08

CL

5.27

LCL

3.45

4.80 3.80 2.80 1

2

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Date/Time/Period

R Diameter (mm) Range



UCL

2.23

CL

0.68

1.50 1.00 0.50 0.00 1

2

Copyright 2014-2015. All rights reserved.

3

4

5

6

7

8

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Date/Time/Period

2016

58

Root Cause Analysis – Sustain 

SPC Charts – Xbar&R Charts 

After processes have been running for a while, and we have additional collectable data points, we can produce an X-bar & R to assess process control more accurately.



The X-bar & R groups individual data points into subgroups (between 2 – 10 data points in one sub-group).



X-bar & R charts are used when you can rationally collect measurements in groups (or subgroups) of between 2 and 10 observations. Each subgroup represents a "snapshot" of the process at a given point in time.



If we use an I & MR for so many data points, it may produce a false alarm at this point.

Copyright 2014-2015. All rights reserved.

2016

59

Root Cause Analysis – Sustain SPC Charts – Xbar&R Charts 7a-3p -1.50 -0.50 0.00 0.00 0.00 -0.50 0.00 0.00 0.50 0.00 0.00 -1.50 -3.00 -2.00 -2.50 -1.50 0.00 0.00 0.00 0.00 0.00 -1.00 -1.00 0.00 -1.00 -0.50 0.00 0.00 -1.00 0.00

3p-7p 0.00 -0.50 0.00 0.00 -1.00 -0.50 0.50 0.00 0.00 0.00 0.50 0.00 0.00 -0.50 -0.50 0.00 -0.50 0.00 0.00 -1.00 -0.50 -0.50 -0.50 0.00 -2.00 -0.50 0.00 0.00 -0.50 0.00

7p-11p 0.00 -0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 -1.00 -1.00 -0.50 0.00 0.00 -0.50 -0.50 -1.50 -0.50 -0.50 0.00 -0.50 -1.00 -0.50 0.00 -0.50 -0.50 -0.50

11p-7a 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 1.00 1.00 0.00 0.00 0.00 0.00 -0.50 0.00 0.00 -1.00 0.00 0.00 0.00 0.00 0.50

X 7a-3p - 11p-7a 1.00 0.50

Average

Days 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

UCL

0.41

0.00 CL

-0.28

LCL

-0.96

-0.50 -1.00 -1.50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Date/Time/Period

R 7a-3p - 11p-7a 4.00 3.00

Range



2.00

UCL

2.13

1.00

CL

0.93

0.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Date/Time/Period

Copyright 2014-2015. All rights reserved.

2016

60

Root Cause Analysis – Sustain 

SPC Charts – Xbar&Sigma Charts  An

X-bar & s(igma) chart is a special purpose variation of the Xbar and R chart.



Sigma represents the standard deviation of the individual samples.



The major difference is that the subgroup standard deviation is plotted when using the Xbar & s chart, while the subgroup range is plotted when using the Xbar & R chart.

 Used

with processes that have a subgroup size of eleven (11) or more, the X-bar & s charts show if the system is stable and predictable.

 Because

standard deviation uses each individual reading to calculate variability, it provides a more effective measure of the process spread as it happens throughout the time data is sampled.

Copyright 2014-2015. All rights reserved.

2016

61

Root Cause Analysis – Sustain 

SPC Charts – Xbar&Sigma Charts  X-bar & Sigma charts are used when you can rationally collect

measurements in groups (subgroups). Each subgroup represents a "snapshot" of the process at a given point in time.  The charts X-axis are time-based, meaning the charts show a history

of the process and one must enter in the sequence from which it was generated.

 For subgroup sizes greater than ten (10) observations, always use

X-bar & Sigma charts, as the Range statistic (R = max – min) is a poor estimator of process sigma for large subgroups.  The subgroup sigma is always a better estimate of subgroup variation

than subgroup range (R). The popularity of the Range chart is only due to its ease of calculation.

Copyright 2014-2015. All rights reserved.

2016

62

Root Cause Analysis – Sustain 

SPC Charts – Attribute Charts 

Attribute charts are the simplest of statistical process control charts to build and interpret.



Attribute charts track measure data that either does, or does not possess a specific characteristic or attribute.



Some examples of attribute data would include: 

% of orders that had all required information before submission to fulfillment.



% of invoices paid within 90 days.



% of customer service emails receiving a reply within specified limit (e.g. 4 hours).



% of customers that rated their satisfaction with services received on the 'favorable' side of neutral.



% of new employees that leave within the first year of employment.

Copyright 2014-2015. All rights reserved.

2016

63

Root Cause Analysis – Sustain 

SPC Charts – Attribute Charts  The

most common attribute charts are

Chart

Records

Subgroup Size

p

Fraction defective

np

Number of defectives

Constant

c

Number of defects

Constant

u

Number of defects per unit

Varies

Percent defectives

Varies

100p

Copyright 2014-2015. All rights reserved.

Varies

2016

64

Root Cause Analysis – Sustain 

SPC Attribute: p Charts 

A p-chart is an attribute control chart used with data collected in subgroups of varying sizes. Because the subgroup size can vary, it shows a proportion on nonconforming items rather than the actual count.



The purpose of a p chart is to evaluate process stability when counting the fraction defective.



The p chart is used when the sample size varies:  Example:

The total number of circuit boards, meals, or bills delivered varies from one sampling period to the next.



Measures % of nonconforming items  Example:

Count # defective chairs & divide by total chairs inspected.



Chair is either defective or not defective.

Copyright 2014-2015. All rights reserved.

2016

65

Root Cause Analysis – Sustain SPC Attribute: p Charts Sample Nonconforming Number Units S1 12 S2 8 S3 6 S4 9 S5 13 S6 12 S7 11 S8 16 S9 10 S10 6 S11 20 S12 15 S13 9 S14 8 S15 6 S16 8 S17 10 S18 7 S19 5 S20 8 S21 5 S22 8 S23 10 S24 6 S25 9

Sample Size 100 80 80 100 110 110 100 100 90 90 110 120 120 120 110 80 80 80 90 100 100 100 100 90 90

Copyright 2014-2015. All rights reserved.

Non-conforming Units

0.25

0.20

Nonconforming Units - Sample Size



UCL

0.190

0.15

0.097 0.10

CL

0.05

0.00

0.003 LCL 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Date/Time/Period

2016

66

Root Cause Analysis – Sustain 

Tools: Communication – RACI(S) 

A RACI matrix or linear responsibility chart (LRC), describes the participation by various roles in completing tasks or deliverables for a project or corrective action.



Not all roles have a responsibility towards implementing a task, and a given task may not be associated to all roles. Typically a task is associated with at least one role or in some cases multiple roles. This ‘Association’ of the role with a task can be divided into the following four association types:    



There is another association type that is sometimes used in addition to the above four types: 



Responsible Accountable Consulted Informed

Supports

When using all the five types in the matrix, it is called a RASCI (pronounced ‘race ski’) Matrix.

Copyright 2014-2015. All rights reserved.

2016

67

Root Cause Analysis – Sustain 

Tools: Communication – RACI Example

Copyright 2014-2015. All rights reserved.

2016

68

Root Cause Analysis

Copyright 2014-2015. All rights reserved.

2016

69