Chapter 16

Question 1

Root cause analysis

Answer 1

four step method called root cause corrective analysis (RCCA)
en effective method for identifying and addressing root causes of sporadic problems and processes

Question 2

The four basic steps of RCCA

Answer 2

Identify a problem
Diagnose the cause
Remedy the cause
Hold the gains

Question 3

Methods for root cause analysis

Answer 3

Plan-Do-Study-Act (PDSA) cycle
Plan-Do-Check-Act (PDCA) cycle
Just do it

Question 4

When to use PDSA and PDCA methods?

Answer 4

useful methods for root cause analysis, planning and executing tests of potentially beneficial changes

Question 5

When to use Just Do It method?

Answer 5

Useful approach when the need to solve a problem is urgent, penalties for risks of failed ‘solutions’ are low, rewards of effective solutions are high

Question 6

Purpose of RCA

Answer 6

to solve problems that occur due to special or assignable causes
sporadic problems - happen periodically

Question 7

Methods to discover root causes

Answer 7

Six sigma DMAIC
Juran’s breakthrough model
RCCA
PDCA
Lean problem-solving
PDSA
Just do it

Question 8

Control

Answer 8

restoring process performance to previously acceptable level
- deals with special causes

Question 9

Improvement

Answer 9

changing the very nature of the process, creating breakthrough, moving to new/better level of performance with reduced waste and COPQ
- deals with common causes

Question 10

To ensure all processes are in a state of control requires three basic elements

Answer 10

1. Means to know actual performance of process
2. Ability to compare actual performance to targets/quality goals
3. Means to act on difference to maintain control (method to determine what correct actions should be taken)

Question 11

PDCA

Answer 11

Plan, Do, Check, Act
a means to set up control functions

Question 12

Juran’s RCCA method

Answer 12

Root cause corrective action
a simple method needed to solve daily, sporadic small-scope problems
1. identify a problem
2. Diagnose the cause
3. Remedy the cause
4. Hold the gains

Question 13

Identify a problem: sub-steps

Answer 13

Is the problem sporadic?
Establish responsibility to solve it
Prepare problem statement

Question 14

Diagnose the cause: sub-steps

Answer 14

Analyse symptoms
Formulate theories
Test theories
Identify root causes

Question 15

Remedy the cause: Sub-steps

Answer 15

Design and implement the remedy

Question 16

Hold the gains: sub-steps

Answer 16

Adjust controls

Question 17

Tools used for RCCA

Answer 17

Affinity method
Brainstorming
Cause-and-effect diagrams
Data collection methods
Failure mode and effects analysis (FMEA)
Graphs, charts

Question 18

Expected outcomes of Root Cause Analysis

Answer 18

Primary output: uncover the root causes of the problem

• Identify weaknesses/other contributing factors
• Better understand the process surrounding the problem as well as supporting processes
• Create an architecture into which you can build your corrective action plan

Question 19

PDSA

Answer 19

Plan, Do, Study, Act

Primarily a guide for identifying root causes through experimentation
Iterative experiments performed to identify root causes

Seeks to confirm/refute ideas of problem causes by trial and error of solutions

Question 20

PDSA steps

Answer 20

1. Plan
   - define change to be tested
   - design experiments to test change
2. Do
   - carry out experimental plan
   - collect data about effectiveness of change
3. Study
   - analyse data from experiment
   - summarise what was learnt
4. Act
   - determine what permanent changes to be implemented
   - determine what additional changes need to be tested

Question 21

Advantages of PDSA

Answer 21

Yield results quickly if experiments are good at selecting solutions that will yield true improvement
Follows experimental approach - yields a great deal of useful knowledge
Widely accepted

Question 22

Disadvantages of PDSA

Answer 22

Can be slow if experiments aren’t good at selecting solutions that will yield true improvements
Changes that don’t succeed may not yield a lot of useful information
Experimentation can be disruptive and resource intensive
Experimentation can be costly

Question 23

Just Do It (JDI)

Answer 23

no root cause analysis involved as root cause is readily apparent
analysing root cause is done entirely by observation

Question 24

To implement JDIs, 3 factors must be present

Answer 24

1) need for change must be urgent
2) change must carry a low cost of failure
3) change must have a significant potential reward