Root Cause Analysis

Presentation on theme: "Root Cause Analysis"— Presentation transcript:

Root Cause Analysis

Welcome to the session!

Objectives

Learn and be able to apply a fishbone diagramUtilize “Why” analysis technique to uncover causes

2

2

“Why” Analysis

Question asking technique used to explore the cause and effect relationships underlying a particular problemFour to five iterations of asking why is generally sufficient to get to a root cause, but may go moreEXAMPLE: The vehicle will not start (problem statement)Why? – The battery is deadWhy? – The alternator is not workingWhy? – The alternator belt is brokenWhy? – The belt was beyond its useful life Why? – The vehicle was not maintained per the recommended schedule

3

Tips For Successfully Using “Why” Analysis

Root cause of the vehicle example appears to be the lack of scheduled maintenance… this is a process that can be improvedYou know when you have gotten to the cause when the answer points to a process that is not working or does not existThe root cause generally is not time, money, or manpowerProcesses fail, not people or money, so ask the question “Why did the process fail?”

4

Why Analysis Example 1

5

Why Analysis Example 2

6

Why Analysis Example 3

7

Why Analysis Example 4

8

9

Why Analysis Example 5

10

Why Analysis Example 6

What is a Fishbone Diagram?

The Fishbone diagram (or Ishikawa Diagram) is used to identify possible causes for an effectCauses are grouped into major categories to identify the sources of variation through the 6M’sManpowerMachinesMaterialsMethodsMeasurementsMother nature [environment]

11

Fishbone Diagram Example 1

12

POOR CRANE

PRODUCTION

New

Driver

Untrained Driver

Driver in Bad Mood

Manpower

Methods

Materials

Machines

Mother Nature

Measurements

Condition of Crane

Broke cell guides

Type of Crane

Additional long travels

Physical Terminal Layout

High

winds

Service Overdue

Operating with Defect

Incorrect Stow Plans

Unrealistic Deadlines

Yard Planning

Stuck Cones

Damaged containers

CAUSES

EFFECT

Fishbone Example 2

13

Fishbone Example 3

14

Why Use a Fishbone?

Groups potential causes for defects into logical categoriesHelps teams work together to get to root cause (inquiry)Highlights where additional data gathering needs to occur

15

Step 1: Determine the Problem/Issue

To construct a fishbone:Start with stating the problem in the form of a question, such as “Why is crane production low?” Agree on the problem (effect) and place it in a box at the “head” of the fishbone

16

Why is Crane production low?

Step 2: Establish the Categories

Determine which categories you will use to find causes and draw the lines (bones)Feel free to modify the categories for your project and subject matterMost common categories called 6 M’s:

17

Manpower

Machines

Materials

Methods

Measurements

Mother nature [environment]

Machines

The Machines category groups root causes related to tools or equipmentExamples of questions to be asked:Was the correct tool/tooling used? Does it meet production requirementsIs the machine properly maintained?Was the equipment used within its capabilities and limitations? Are all controls clearly labeled and/or color-coded or differentiated?

18

Y

Machines

Methods

The Method category groups root causes related to how the work is doneExamples of questions to be asked:Are the work instructions clearly written & complete?Are mistake-proofing devices/techniques employed?How many “if necessary” and “approximately” phrases are found in this process?Are features of the process critical to safety clearly spelled out?Is the work standard upgraded and to the current revision?

19

Y

Methods

Materials

The Materials category groups root causes related to parts, supplies, forms or information needed to execute the processExamples of questions to be asked:Is all needed information available and accurate?Was the material substituted?Was the material defective?Was the raw material the wrong type for the job?Was the material handled properly(stored, dispensed, used & disposed)?

20

Materials

Y

Measurements

The Measurement category groups root causes related to the measurement and measuring of a process activity or outputExamples of questions to be asked:Is there a metric issue?Is there a valid measurement system? Is the data good enough?Is data readily available?Does the measuring gage have proper measurement resolution?

21

Measurements

Y

Manpower

The Manpower category groups root causes related to people, staffing and organizational structureExamples of questions to be asked:Was the proper training to perform the task administered to the person? Was too much judgment required to perform the task? Were guidelines for judgment available? Is fatigue a contributing factor? How much experience does the individual have in performing this task?

22

Manpower

Y

Mother Nature (Environment)

The Mother Nature category groups root causes related to the work environment, market conditions, and regulatory issuesExamples of questions to be asked:Is the workplace safe and suitable/ comfortable? Are outside regulations impacting the business?Is the process affected by temperature changes over the course of a day?Are associates distracted by noise, uncomfortable temperatures, fluorescent lighting, etc.?

23

Y

Mother Nature

Step 3: Brainstorm Causes

For each category, brainstorm possible root causes of the problem that may be related to the problem/ issueFor each cause identified, continue to ask “why does that happen?” and attach that information as another line (bone) of the category branch

24

Step 4: Review the Diagram

The diagram should now show all of the possible causes of the problem that you can think ofPrioritize the key causes identified on the fishboneAgree on which of these possible causes are actually contributing

25

Summary

Identify the problem or issueDraw horizontal line across center of pageWrite problem at fish headEstablish the categoriesUse the 6M’s: Manpower, Machine, Method, Measurement, Material, Mother Nature (Environment) - or choose your ownDraw lines (bones) and the labelsBrainstorm/ record ideas onto fishboneCreate sub-branches as neededReview completed diagram and set focusScore / Vote or Rank as appropriate to group thoughts, or prioritize the issues by data analysis (most frequently occurring) or cost impact on the process or risk of failure/ work stoppage, etc.

26

Exercise: Create a Fishbone Diagram

With your team, construct a detailed Cause and Effect Diagram on the process / example presentedIdentify and label categoriesExamine using the “why” analysisBrainstorm as many inputs as possible with each branch and/ or sub-branch

27

Review

Learn and be able to capture thoughts using a fishbone diagramLearn to apply “Why” analysis technique to uncover root causes

28