[ppt]quality improvement: problem solving - saint...

Quality Improvement: Problem Solving

Week 6AgendaAgenda Review homework

• Problems Ch 3: 2, 4 Ch 3: Quality tools desksides

• Flow chart• Pareto Diagram• Histogram• Cause and Effect Diagram• Check sheet• Scatter diagram• Control chart• Why-why• Force field analysis• Brainstorming

Week 7 assignment • Read chapter 4• Homework problems:

Ch 3 - 9, 11, 33• Case Study: "How

We Slashed Response Time"


Quality ToolsQuality ToolsChapter 3: Problem Solving


Quality Control ToolsQuality Control Tools• Pareto chart• Histogram • Process flow diagram• Check sheet• Scatter diagram• Control chart

• Run chart• Cause and effect diagram


Pareto PrinciplePareto Principle Vilfredo Pareto (1848-1923) Italian

economist• 20% of the population has 80% of the

wealth Juran used the term “vital few, trivial

many”. He noted that 20% of the quality problems caused 80% of the dollar loss.

7 Quality Tools7 Quality Tools


Pareto chartPareto chart


28

1612 12

64 3

0

5

10

15

20

25

30

LooseThreads

Stitchingflaws

Buttonproblems

Materialflaws

% C

ompl

aint

s


Pareto Pareto Chart Chart

Per

cent

from

eac

h ca

use

Causes of poor quality

Machin

e cali

brati

ons

Defecti

ve pa

rts

Wro

ng di

mensio

ns

Poor D

esign

Opera

tor er

rors

Defecti

ve m

ateria

ls

Surfac

e abr

asion

s

0

10

20

30

40

50

60

70(64)

(13)(10)

(6)(3) (2) (2)


HistogramHistogram

0

5

10

15

20

25

Category

Freq

uenc

y



HistogramHistogram

05

10152025303540

1 2 6 13 10 16 19 17 12 16 20 17 13 5 6 2 1


FlowchartsFlowcharts Flowcharts

• Graphical description of how work is done.• Used to describe processes that are to be

improved.



Flow DiagramsFlow Diagrams" Draw a flowchart for whatever you do. Until you do, you do not know what you are doing, you just have a job.”

-- Dr. W. Edwards Deming.


FlowchartActivity

DecisionYesYes

NoNo



FlowchartFlowchart


Flow DiagramsFlow Diagrams

Process Chart SymbolsProcess Chart Symbols

Operations

Inspection

Transportation

Delay

Storage


Process ChartProcess ChartSt

ep

Ope

ratio

nTr

ansp

ort

Insp

ect

Del

aySt

orag

e

Dis

tanc

e(fe

et)

Tim

e(m

in)Description

ofprocess

123456789

1011

Unload apples from truckMove to inspection stationWeigh, inspect, sortMove to storageWait until neededMove to peelerApples peeled and coredSoak in water until neededPlace in conveyorMove to mixing areaWeigh, inspect, sort

TotalPage 1 0f 3 480

30

52015

360

30

20

190 ft

20 ft

20 ft

50 ft

100 ft

Date: 9-30-00Analyst: TLR

Location: Graves MountainProcess: Apple Sauce


Check SheetCheck Sheet

ShiftsShifts

Def

ect T

ype

Def

ect T

ype



Check SheetCheck Sheet

COMPONENTS REPLACED BY LABTIME PERIOD: 22 Feb to 27 Feb 1998REPAIR TECHNICIAN: Bob

TV SET MODEL 1013

Integrated Circuits ||||Capacitors |||| |||| |||| |||| |||| ||Resistors ||Transformers ||||CommandsCRT |


Cause-and-Effect DiagramsCause-and-Effect Diagrams Show the relationships between a

problem and its possible causes. Developed by Kaoru Ishikawa (1953) Also known as …

• Fishbone diagrams• Ishikawa diagrams



Cause and Effect Cause and Effect “Skeleton”“Skeleton”

QualityProblem

Materials

EquipmentPeople

Procedures



Fishbone Diagram Fishbone Diagram

QualityProblem

MachinesMeasurement Human

ProcessEnvironment Materials

Faulty testing equipment

Incorrect specifications

Improper methods

Poor supervision

Lack of concentration

Inadequate training

Out of adjustment

Tooling problems

Old / worn

Defective from vendor

Not to specifications

Material-handling problems

Deficienciesin product design

Ineffective qualitymanagement

Poor process design

Inaccuratetemperature control

Dust and Dirt


Cause and effect diagramsCause and effect diagrams Advantages

• making the diagram is educational in itself• diagram demonstrates knowledge of

problem solving team• diagram results in active searches for

causes• diagram is a guide for data collection


Cause and effect diagramsCause and effect diagrams

To construct the skeleton, remember: For manufacturing - the 4 M’s

man, method, machine, material For service applications

equipment, policies, procedures, people


Scatter DiagramScatter Diagram

.


Run ChartsRun Charts Run Charts (time series plot)

• Examine the behavior of a variable over time.

• Basis for Control Charts


Control ChartControl Chart

18

12

6

3

9

15

21

24

27

2 4 6 8 10 12 14 16

Sample number

Num

ber o

f def

ects

UCL = 23.35

LCL = 1.99

c = 12.67


Control ChartsControl Charts



““Stem and leaf” displaysStem and leaf” displays

4.6 4.0 3.7 4.1 4.1 5.6 4.5 6.0 6.0 3.43.4 4.6 3.7 4.2 4.6 4.7 4.1 3.7 3.4 3.33.7 4.1 4.5 4.6 4.4 4.8 4.3 4.4 5.1 3.9

DataIntegrated Circuit Response Time (ps)


““Stem and leaf” displaysStem and leaf” displays

3 7 4 4 7 7 4 3 7 9

4 6 0 1 5 6 2 6 7 1 1 5 6 4 8 3 4

5 6 1

6 0 0

Integrated Circuit Response Time (ps)


Dot diagramsDot diagrams

3 4 5 6Plant A

Plant B

Integrated Circuit Response Time (ps)

[ppt]quality improvement: problem solving - saint...

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