1. CHAPTER 3: QUALITY IMPROVEMENT
Outline
Process improvement
PDSA cycle
Process improvement steps
Tools

2. Plan Act Study The P-D-S-A Cycle Do
Identify problem. Develop plan for improvement. Do
Act
Institutionalize improvement. Continue cycle.
Implement plan
on test basis
The P-D-C-A cycle, promoted by Deming, is the basis for continuous improvement. It differs from traditional problem solving in that problems are prioritized and addressed one at a time, and a solution is implemented on a small scale first and verified that it works before implementing on a large scale. After the most important problem has been solved, the group moves on to the problem, cause or solution with the next highest priority and follows the same cycle. This repetitive enactment of the cycle creates a spiral of improvement that can continue indefinitely.
Study
Is the plan working?

3. Steps in Process Improvement
Plan
1: Recognize problem
2: Form quality improvement teams
3: Define problem
4: Develop performance measures
5: Analyze problem
6: Determine possible causes

4. Steps in Process ImprovementDo
7: Implement solution
Study
8: Evaluate solution
Act
9: Ensure performance
10: Continuous improvement

5. Plan: Steps 1 and 2 1: Recognize problem
Existence of the problem is outlined
In general terms, specifics are not clearly defined
Solvability and availability of resources are determined
2: Form quality improvement teams
Interdisciplinary
Specified time frame
Quality circle

6. Plan: Step 3 3: Define the problem Define the problem and its scope
Pareto analysis
Brainstorming
Why-why diagram

7. Pareto Chart 50 100 80 30 60 40 10 20 Cumulative percentage
Number of defects
100 80 60 40 20 50 30 10
Cumulative percentage
The next sequence translates the data from the checklist to a Pareto chart. 10

8. Pareto Chart 50 100 80 30 60 C 40 10 20 Cumulative percentage
Defect type C D A B
Number of defects
100 80 60 40 20 50 30 10
Cumulative percentage
The four defect types are charted with the chart height being the relative frequency of occurrence and the defects ordered in descending order of magnitude. This is a discrete chart, one of the two ways Pareto charts are commonly constructed. 11

9. Pareto Chart 50 100 80 30 60 C 40 10 20 Cumulative percentage
Number of defects
100 80 60 40 20 50 30 10
Cumulative percentage
Defect type C D A B
This chart adds the cumulative line to the chart showing the alternate charting technique. 12

10. Percent from each cause
Pareto Chart 10 20 30 40 50 60 70
(64)
Percent from each cause
(13)
(10)
(6)
(3)
(2)
(2)
Pareto analysis uses an ordered histogram to highlight the major causes of quality problems.
Poor Design
Defective parts
Machine calibrations
Operator errors
Wrong dimensions
Defective materials
Surface abrasions
Causes of poor quality

11. Why-Why Diagram A technique to understand the problem
Does not locate a solution
The process leads to many reasons the original problem occurred
Example: A mail-order company has a goal or reducing the amount of time a customer has to wait in order to place an order. Create a why-why diagram about waiting on the telephone.

12. Why-Why Diagram Workers not scheduled at peak times Why? Waiting on
the phone
to place
an order
Insufficient operators
available
Why?
Why?
Low pay
Many customers calling at the same time
All catalogs shipped at the same time
Why?
Why?

13. Plan: Step 4 4: Develop performance measures
Set some measurable goals which will indicate solution of the problem
Some financial measures: costs, return on investment, value added, asset utilization
Some customer-oriented measures: response times, delivery times, product or service functionality, price
Some organization-oriented measures: employee retention, productivity, information system capabilities

14. Plan: Steps 5 and 6 5: Analyze problem
List all the steps involved in the existing process and identify potential constraints and opportunities of improvement
Flowchart
6: Determine possible causes
Determines potential causes of the problem
Cause and effect diagrams, check sheets, histograms, scatter diagrams, control charts, run charts

15. Flowchart Operation Delay Storage Transportation Inspection Decision
A flowchart diagrams the steps in a process. Flowcharts help problem solvers better understand the process so they can highlight quality problems.

16. Flowchart Enter emergency room Fill out Nurse patient Walk to
history
Nurse
inspects
injury
Walk to
triage room
Return to
waiting
room
Wait
for ER bed
Walk to
ER bed
A flowchart diagrams the steps in a process. Flowcharts help problem solvers better understand the process so they can highlight quality problems.
Walk to
Radiology
Doctor
inspects
injury
Wait
for
doctor

17. Flowchart Walk to radiology Technician X-rays patient Wait for
doctor to
return
Doctor
provides
diagnosis
Return to
ER bed
Return to
Waiting
A flowchart diagrams the steps in a process. Flowcharts help problem solvers better understand the process so they can highlight quality problems.
Leave
Building
Walk to
pharmacy
Pickup
prescription
Checkout

18. Cause and Effect Diagram
Common categories of problems in manufacturing
5 M’s and an E
Machines, methods, materials, men/women, measurement and environment
Common categories of problems in service
3 P’s and an E
Procedures, policies, people and equipment

19. Cause and Effect Diagram
Measurement
Men/Women
Machines
Faulty testing equipment
Poor supervision
Out of adjustment
Incorrect specifications
Lack of concentration
Tooling problems
Improper methods
Inadequate training
Old / worn
Quality
Problem
Inaccurate
temperature
control
Poor process design
Defective from vendor
Ineffective quality
management
Not to specifications
Dust and Dirt
Material-
handling problems
Deficiencies
in product design
Environment
Materials
Methods

20. Check Sheet Integrated Circuits ||||
COMPONENTS REPLACED BY LAB
TIME PERIOD: 22 Feb to 27 Feb 1998
REPAIR TECHNICIAN: Bob
TV SET MODEL 1013
Integrated Circuits ||||
Capacitors |||| |||| |||| |||| |||| ||
Resistors ||
Transformers ||||
Commands
CRT |
A check sheet is a fact-finding tool used to collect data about quality problems. A typical check sheet tallies the number of defects by previously identified categories. The next step is to graph the defects per category in a histogram.

21. Telephone call duration, min
Histogram 5 10 15 20 25 30 35 40
Frequency of calls
Histograms are graphical frequency tables that visually capture and display the variation in a set of data.
Telephone call duration, min

22. Scatter Diagram Number of tears . Rotor speed, rpm
Scatter diagrams and tightness of points plotted on the graph gives an indication of the strength of the relationship. A cluster of points resembling a straight line indicates the strongest correlation between the variables. In this graph, there is a strong positive correlation between x and y.
Rotor speed, rpm

23. Control Chart 27 24 UCL = 23.35 21 c = 12.67 18 15 Number of defects9
Process control involves monitoring a production process and charting the results on a control chart. If any of the points plotted falls outside the control limits, the process is out-of-control. 6
LCL = 1.99 3 2 4 6 8 10 12 14 16
Sample number

24. Do: Step 7 7: Implement the solution The solution should
prevent a recurrence of the problem
address the root cause of the problem
be cost effective
be implemented within a reasonable amount of time
Force-field analysis

25. Do: Step 7 Force-field analysis A chart that lists
the positive or driving forces that encourages improvement as well as
the restraining forces that hinders improvement
Actions necessary for improvement

26. Do: Step 7
Example: create a force-field diagram for the following problem:
Bicycles are being stolen at a local campus. Campus security is considering changes in the bike rack design, bike parking restrictions and bike registration to try to reduce thefts. Thieves have been using hacksaws and bolt cutters to remove locks from the bikes

27. Reading
Chapter 3:
Reading pp (2nd ed.), pp (3rd ed.)