Basics of Quality Circle

1. 1
WORKSHOP
ON
QUALITY CIRCLE
OPERATION & PRESENTATION

2. 2
OBJECTIVE OF THE PROGRAMME
The objective of the Program is to make the Quality Circles
operating in the various areas more effective and result
oriented. This will focus on improving the knowledge and
application of QC Tools, which will help in problem
identification, collection and analysis of data, finding of
actual causes and their root causes, its solution, evaluation
of results and making a successful presentation.

3. 3
WHAT IS A QUALITY CIRCLE?
It is a small group of people in an organisation
from the same or similar work area, which meets at
regular intervals to identify, analyse, discuss and
solve work related problems.

4. 4
WHAT QUALITY CIRCLES ARE NOT?
• Not just a meeting for having tea.
• Not a forum for grievances.
• Not a spring board for demands.
• Not a tool for management to unload
problems.

5. 5
KEY POINTS
 A SMALL HOMOGENOUS GROUP.
 OPTIMUM SIZE IS 5 TO 10 MEMBERS INCLUDING THE
LEADER.
 MEETS REGULARLY ON A DECIDED DAY, PLACE AND
TIME ONCE A WEEK OR FORTNIGHT.
 SOLVES WORK RELATED PROBLEMS.
 ELECTS ITS OWN LEADER TO FUNCTION AS A TEAM

6. 6
WHY QUALITY CIRCLES?
• PROVIDES OPPORTUNITY TO DISPLAY CAPABILITIES.
• PROVIDES AN OPPORTUNITY TO LEARN AND GROW.
• DEVELOPS PROBLEM SOLVING ATTITUDE AND QUALITY CONCIOUSNESS.
• HELPS IN REDUCTION OF DEFFECTS AND COST RESULTING INCREASE IN
PRODUCTIVITY.
• IMPROVES TEAM WORK.
• IMPROVES COMMUNICATION SKILL.
• MOTIVATES EMPLOYEES THROUGH REWARDS AND RECOGNITION.
• IMPROVES LABOUR- MANAGEMENT CO-OPERATION.

7. 7
STEERING COMMITTEE
 Policy making body and establishes operational guidelines.
 Evaluate circle project and monitors.
 Support, encourage, and reward circles.
 Review of recognition and rewards to circles.
CO-ORDINATOR
 Secretariat to the steering committee.
 Co-ordinates and directs QC activities.
 Backs up facilities for training of members.
 Maintains appropriate QC records.
 Follows circles project work.
 Organises divisional and external presentation

8. 8
FACILITATOR
 Responsible for successful operation of his
QC.
 Ensures necessary facilities for QC
 Helps in collection of Data, use of Q.C tools.
 Trains QC members to prepare for successful
presentation.
 Interacts with steering committee and co-
ordinator.
 Maintains and communicates records.

9. 9
LEADER
 Conducts Q.C meeting regularly.
 Maintains harmonious and humorous atmosphere during
meetings.
 Responsible for successful operation of his QC
 Interacts with Facilitator to get needed support.
 Maintains records / Register of his circle.
 Ensures participation and involvement of members.
 Ensures consensus approach in all decisions.
 Chalks out plan and assigns responsibility.
 Interacts with other functional areas, if required.
 Prepares circle for management presentation.
DY LEADER
Responsible for all the jobs of leader in his absence.

10. 10
MEMBERS
Members are the most important persons and without
them there can be no activity. They are the heart of the
circle and proper utilisation of their knowledge,
experience and creative idea, is the key to its success.
They -
 Attend meetings regularly and in time.
 Participate in discussion.
 Follow code of conduct.
 Learn QC Tools and apply them.
 Contribute in solving problems
 Help in solution implementation

11. 11
PROBLEM IDENTIFICATION
Problems are identified by brain storming amongst members. Since
members are the most knowledgeable and experienced on their
Products, Processes and Machines, they know the problems being faced
by them during their day to day work.
A Check-List for Problem Identification:
Variation in product -
 Quality / Size / Weight
Product non-conformity -
Rejection
Repair
Rework
Process / Equipment related -
High Cycle / Lead Time
Low productivity
High problem frequency
Difficulty in working
Cost Reduction -
Consumption of Power, Comp. Air, Spares, stores items,
Use of Scrap, Rejection, repaired spares,
Productivity
Safety - Chance of accidents
House-keeping and Environment
Contamination
Leakage/ wastage of Oil, Water, Dust, Fumes

12. 12
PROBLEM SELECTION
When problems are many, the members discuss for
selection of a problem for solving.
Prioritisation of problems are done considering one or
more of following factors:
 Product quality
 Safety hazards
 House Keeping
 Project Time
 Urgency for Solution
 Scope of Improvement
 Customer satisfaction
 Scope of Cost Reduction

13. 13
NOMINAL GROUP TECHNIQUE
(NGT)
Problem Mr A Mr B Mr C Mr D Mr E Total
Rating
1 10 9 8 10 11 48
2 8 9 6 7 5 35
3 8 8 7 6 4 33
4 12 11 13 11 12 59
5 6 6 5 6 5 28
Factors considered for Rating (Scale: 1 to 5)
• Customer Satisfaction
• Cost reduction
• Project time

14. 14
Q C TOOLS & TECHNIQUES
The seven basic QUALITY CONTROL TOOLS used
in Quality Circle are:
CHECK SHEET
STRATIFICATION
HISTOGRAM
SCATTER DIAGRAM
PARETO DIAGRAMS
GRAPH AND CONTROL CHARTS
CAUSE AND EFFECT DIAGRAM

15. 15
CHECK SHEET
Check Sheet is a method by which data collection
is made easier and systematic. Check sheet should
be made simple and useful. A format should be
prepared to ensure that all the data are conveniently
collected.

16. 16
Check Sheet for collection of frequency / occasions:
Sr
No
Problem/
Cause
Frequency / No. of Occasions Total
1 Lamination ++++ ++++ ++++ ++++ ++++
++++ ++++ ++++
42
2 E/C breakage ++++ ++++ ++++ ++++ 23
3 Over size ++++ ++++ 10
4 Spongy ++++ ++++ ++++ 15
5 Body crack ++++ 5
6 Short size ++++ 5

17. 17
STRATIFICATION
Some times problems are best understood in pieces, rather than as a
whole.
Dividing a group of measurements into several group characteristics is
called Stratification.
Example:
The problem is of LOW PRODUCTIVITY in press section.
The average productivity is 82%.
By Stratification, we can find out the extent of problem in different
Press Groups. Stratification helps to identify the area where the impact
of the problem is more. We can further collect the data shift-wise to
know whether the problem is in all the three shift or more in a particular
shift.

18. 18
productivity %
Press Average 82
FSP 150 87
FSP 400 77
Horn Press 90
82
87
77
90
70
72
74
76
78
80
82
84
86
88
90
PRESS
Press Average
FSP 150
FSP 400
Horn Press

19. 19
Productivity in FSP 400:
Shift Mon Tue Wed Thurs Fri Sat Sun
A 72 75 71 70 73 71 70
B 82 81 83 85 81 83 85
C 87 88 90 85 88 90 91
Line Graph
0
20
40
60
80
100
Days
Productivity%
A
B
C

20. 20
HISTOGRAM
A Histogram is a form of Column / Bar graph, which displays
the distribution of values obtained whenever numerical data is
collected. It is a series of columns, placed side by side that
normally would take on a bell shape.
HISTOGRAM is used to represent the range of variation in a
group of data from its mean value. It gives an idea at a glance
about the process from which the data was collected. It is a
finger print of the process when a large data are collected.

21. 21
Exercise:
Draw a HISTOGRAM showing the variation in thickness of brick size
230x115x76mm. The thickness measured are:
76.0, 75.4 , 76.6 , 75.6 , 76.4 , 75.6 , 76.4 , 76.0, 75.8 , 76.2 , 75.8, 76.0, 76.2 , 76.0, 75.8 ,
76.2 , 75.8 , 76.2 , 76.0 , 76.0
Size 75.4 75.6 75.8 76.0 76.2 76.4 76.6
Nos. 1 2 4 6 4 2 1
Histogram
0 2 4 6 8
1
Thickness
Frequency / Numbers
Upper Tolerance Limit
Lower Tolerance Limit
76.0 ± 1
76.6
75.4
77.0
75.0
76.0

22. 22
SCATTER DIAGRAM
Scatter diagram is drawn to show the distribution of a group of data
on a graph. Each data is represented by a different point on the
graph. After a large number of data are plotted, an average trend line
is drawn which indicates the relationship between the two variables
used in the graph.
Scatter Diagram
40
50
60
70
80
90
100
2 3 4 5 6 7
Running hours
Productivity%

23. 23
PARETO DIAGRAM
Exercise:
Sr NO Problem / Trouble %
1 Lamination 42
2 E/C Breakage 23
3 Over size 8
4 Spongy 15
5 Body crack 3
6 Short size 4
7 Bend / Warpage 3
8 Pin holes 2
PARETO diagram combines two of the common form of graphs, a column
graph and a Line graph. The Pareto analysis helps to identify the VITAL few
from TRIVIAL / USEFUL MANY and guides which problems / causes will
give maximum results, if solved.
The complete analysis is depicted in a graph form with columns arranged in
descending order. Each column represents a different problem / cause. A
few taller ones on the left ( about 20 % of problems / causes), if solved, will
give about 80 % of results. The total problems selected for solving also
gives the extent of expected results. This can be used for setting the
TARGET of the OBJECTIVE.

24. 24
42
23
15
8 4 3 3 2
0
10
20
30
40
50
60
70
80
90
100
Problems / Defects
Lamination
E/C Breakage
Spongy
Over size
Short size
Bodycrack
Bend / Warpage
Pinholes
100
65
80
88

25. 25
Pareto Chart
42
23
15
8
4 3 3 2
42
65
80
88
92
95
98 100
0
20
40
60
80
100
120
Lam
inationE/C
Breakage
Spongy
O
versize
Shortsize
Body
crack
Bend
/W
arpage
Pin
holes
Problems / causes
%
Cumm.%
%
cumm. %

26. 26
GRAPH AND CONTROL CHARTS
Following are the different kinds of graphs used in QC:
LINE GRAPH
BAR CHART
PIE CHART
PIE CHART
42
23
8
15
34 32
Lamination
E/C Breakage
Over size
Spongy
Body crack
Short size
Bend / Warpage
Pin holes

27. 27
CAUSE & EFFECT DIAGRAM / FISH-BONE DIAGRAM /
ISHIKAWA DIAGRAM
Cause Group Cause Group
Cause Group Cause Group
EFFECT
Cause Groups may be:
•Man
•Machine
•Material
•Method
•Environment or any other relevant Group
Write down all expected probable causes under each relevant cause group.

28. 28
Cause Group
EFFECT
CAUSE
Sub cause
Root cause
Cause
ASK 5 TIMES WHY? TO FIND OUT ROOT CAUSE:
1. Ask WHY ? after identifying a cause.
The answer will give the Sub-cause.
2. Ask again WHY ?
The answer will give next Sub-cause.
3. Ask again Why ?
4. Continue the exercise till you get no further answer.
The last answer is the Root Cause.

29. 29
METHOD: EXAMPLE:
Sr Nr Steps Write Under
1 What is the trouble? Effect High Lamination
2 Which are relevant cause-groups? Cause-group Press, Mould, Mixture, Operator, Brick
3 Draw Process-Matrix of the process Effect - High Lamination
where the problem got detected. process Process - Pressing
control Inputs - Mixture quality and quantity,
inputs process output Mould, Press, Operator,
Trouble Brick - Shape / Size
(Effect)
4 Consider any one cause-group and Cause-group - Mixture:
brain-storm to determine causes for Effect 1st stage Cause High / Low Moisture High Fines High Temp
5 Ask - why this Trouble was there? Reason in Sub-cause Variation in addition Variation in Less Ageing time
6 Ask again - why this Trouble was there? Reason in Sub-cause Inaccurate measuring quantity by Summer season
If needed, go to previous process. device Damper
7 Ask again - why this Trouble was there? Reason in Root cause Existing design Existing design High environ temp
If needed, go to further previous process.

30. 30
METHOD: EXAMPLE:
Sr Nr Steps Write Under
1 What is the trouble? Effect Out pressing of moulds
2 Which are relevant cause-groups? Cause-group Press, Mould, Mixture, Operator,
3 Draw Process-Matrix of the process Effect - Out pressing of moulds
where the problem got detected. process Process - Pressing
control Inputs - Mixture quality and quantity,
inputs process output Mould, Press, Operator,
Trouble
(Effect)
4 Consider any one cause-group and Cause-group - Mould:
brain-storm to determine causes for Effect 1st stage Cause Mould centre out Top plate centre out
5 Ask - why this Trouble was there? Reason in Sub-cause Studs got loosened Plunger out of centre
6 Ask again - why this Trouble was there? Reason in Sub-cause Studs got elongated : Guide rod losened
If needed, go to previous process. 1.MS studs used 2. High Bot.pressing Lock was not provided
7 Ask again - why this Trouble was there? Reason in Root cause HT Studs not available Less material fed Carelessness of fitter
If needed, go to further previous process. Indent qty not increased Spring balance trouble Lack of training
as per requirement Low balance accuracy

31. 31
Other Problem Solving Tools
BRAIN STORMING:
The Brain Storming is used when the circle wants
 To identify problems
 To find out actual causes and making Cause and Effect
diagram
 To develop alternate solutions
The pre requisites for successful Brian Storming session are:
•A relaxed atmosphere which can readily accommodate
laughter
•All members must be informed about the specific purpose of
the session
•All ideas should be recorded
•All should participate.
The rules of brain storming session:
No criticism.
Discuss what is wrong and not who is wrong.
More fun you have, more creative the session will be.
More suggestions from each member are desired.
Combination and improvement is sought.

32. 32
SELECT THE BEST SOLUTION
There may be more than one alternate solution for a problem. When the
situation is like that, the best of all alternatives is to be selected.
However the decision should be consensus, not by majority. The "best
solution" is selected considering some relevant factors of the following:
 Ease of implementation
 Safety
 Implementation time
 Money investment
 User friendliness
 Urgency / Importance of the solution
 Feasibility of solution
Customer satisfaction

33. 33
DECISSION MATRIX
Solution Ease of
Implementation
Cost of
Implementation
Customer
Satisfaction
Total
Rating
X 1 1 3 5
Y 5 2 3 10
Z 5 5 5 15
Factors considered for rating (Scale: 1 to 5)
• Ease of implementation (low to high)
• Cost of implementation (high to low)
• Customer satisfaction (low to high)

34. 34
MANAGEMENT APPROVAL
Before Implementation, the QC should present their findings before
the Head of Dept or Management for approval. The Facilitator of the
circle should take up the responsibility.
The management then reviews the recommendation (solution)
suggested by the QC and after analysing gives the approval for
implementation with necessary guideline or advice, as necessary.

35. 35
IMPLEMENTATION
This is the most important phase of the QC activity and gives real
satisfaction to the members if the implementation is successful.
But it requires close monitoring. The facilitator should provide all
necessary guidance and help, required from other areas for
successful implementation.

36. 36
REVIEW OF RESULTS
A Solution once implemented may not be 100% perfect and
may need further modification / improvement. So the
difficulties being faced by Users and results must be
recorded, monitored for adequate duration and reviewed
for further improvement.
Deming's PDCA cycle helps us to carry out our work /
project very systematically with continuous
improvements.

37. 37
P-D-C-A CYCLE
ACT PLAN
(What you need to do)
(Take action to achieve
planned results)
CHECK DO
(Measure achieved vs (What you have
planned and identify planned)
reasons)

38. 38
STORY OF A KINGDOM
PRESENT SITUATION:
• PEOPLE COME WITH PROBLEMS OF VARIOUS TYPES TO THE
KING
• ONE PROBLEM IS NOT YET SOLVED, OTHERS SPRING UP.
• KINGDOM IS NOT PROSPERING.
THE KING CALLS FOR THE WISEST MAN (CONSULTANT),
EXPLAINS THE SITUATION OF EVER-INCREASING PROBLEMS.

39. 39
WISE MAN- HOW DO YOU KNOW THEY ARE MULTIPLYING ?
KING - WE MAINTAIN A LOG BOOK.
WISE MAN- WHAT KINDS OF PROBLEMS ?
KING - ALL TYPES OF PROBLEMS RELATED TO SEEDS, CROP,
IRREGATION, FINANCE, HOUSING, ARMIES, ETC.
WISE MAN- YOUR PALACE IS QUITE BIG, HAVING DOZENS OF ROOMS.
I OBSERVED WHILE COMING THAT PALACE WAS MAINTAINED
CLEANED. SERVANTS ARE NOT MANY AND THEY SEEMED TO
BE HAPPY.
HOW DO YOU KEEP THE PALACE CLEAN AND SERVANTS
HAPPY?
QUEEN- VERY EASY. WE ALWAYS CLEAN THE BIGGEST AND
DIRTIEST ROOM FIRST.
WISE MAN- HOW DOES IT HELP ?
QUEEN- IT CREATES A SENSE OF ACHIEVEMENT ON COMPLETION
OF A BIG TASK AND IT MOTIVATES THE SERVANTS TO
CLEAN OTHER ROOMS HAPPILY.

40. 40
WISE MAN - THE ANSWER TO YOUR PROBLEM LIES HERE
PALACE KINGDOM
DIRTY ROOMS VARIOUS PROBLEMS
DIRTIEST ROOM BIGGEST PROBLEM
SOLUTION – CLEAN IT IDENTIFY & SOLVE IT
CLEAN OTHER ROOMS
ONE BY ONE
SOLVE OTHER PROBLEMS
ONE BY ONE
SENSE OF ACHIEVEMENT SENSE OF ACHIEVEMENT
SO, LET US SOLVE THE BIGGEST PROBLEMS OF
THE KINGDOM

41. 41
PROBLEM
DEFINE - ANNUAL FOOD PRODUCTION PRODUCTION HAS
BEEN FALLING FOR LAST 3 YEARS.

42. 42
IDENTIFY BIGGEST PROBLEM IN THE AREA OF FOOD
PRODUCTION

43. 43
MEASURE AND STATE THE PROBLEM WITH TARGET
ANNUAL RICE PRODUCTION
RICE PRODUCTION, WHICH ACCOUNTS FOR 46% OF THE
TOTAL AGRICULTURAL OUTPUT, HAS BEEN FALLING AT A
RATE OF 7 % TO 10% PER YEAR FOR THE LAST 3 YEARS
AND MUST BE INCREASE BY 30 % IN 1995.

44. 44
ANALYSE THE PROBLEM
TO FIND CAUSES OF POOR RICE PRODUCTION
BRAIN STORMING BY KNOWLEDGEABLE & EXPERIENCED FARMERS
ROOT CAUSES :
DETERIORATION OF SOIL DUE TO REPEATED PLANTING OF RICE.
LACK OF TRAINING IN FARMERS
WATER SOIL
No Rains
No Fertilizer
Deterioration
No Canals Lack of money
Lack of Money Repeat Crop
Declining
Rice Production
Poor Quality
Lack of money Lack of Training
SEED FARMER

45. 45
FIND SOLUTIONS TO ELIMINATE ROOT CAUSES:
• ROTATING BEANS WITH RICE
• USE OF ANIMAL WASTE AS FERTILISER
• PROVIDE TRAINING
ACTION PLAN & RESPONSIBILITIES:
EVALUATE RESULTS :
THE CROP INCREASED BY 35 %
STANDARDISE THE IMPROVEMENTS:
TAKE–UP NEXT PROBLEM / CAUSE:

46. 46

47. 47
22 STEPS FOR PROBLEM SOLVING AND PRESENTATION
Sr
No
STEPS QC TOOLS
1 Introduction and Circle profile
2 Identify problems and submit a list to
r Co-ordinator
Past Performance
Data,
Brain-storming
3 Prioritise problems and select one NGT, Pareto Chart
4 Define selected problem in
measurable terms
(5W & 1H) What,
where, when,
whom, who, how?
5 Roadmap with stage-wise completion
date
Gannt Chart
6 Collect data about problem and its
impact in measurable terms
Flow chart, Past
data, Check sheet,
Histogram,
Stratification,
Scatter Diagram,
Control Chart
7 Set measurable and time bound Target SMART
8 Draw Cause and Effect diagram
finding the expected probable causes
Brain storming,
Cause and Effect
Diagram,
9 Find out sub-causes and root causes Ask 5 times WHY?
10 Collect / generate data to establish
Root causes. If not possible to collect
data, it may be established based on
experience of members.
Check Sheet,
Histogram,
Control Chart,
Stratification,

48. 48
11 Select actual Root cause/s with high
impact. Reset the Target, if necessary.
Pareto Chart
Pie Chart
12 Find alternate Solutions for selected
actual Root causes.
Brain storming
5Ws and 1H Technique
13 Select the best workable solution. Also
find ways to overcome resistance.
Decision matrix
Brain storming
14 Get approval of HOD for its
implementation
15 Draw Implementation Plan with
responsibility and completion date
Activity / Gannt Chart
16 Measure and monitor results and
evaluate before and after solution
implementation
Check-List, Check-Sheet,
Tabulated data, Control
chart, Bar/Line/ Pie Graph
17 Discuss and take actions for further
improvement, as necessary.
Brain storming
18 Define Tangible and Intangible Benefit
19 Action plan for Holding the gains Check-List, Monitoring
result
Training / Maint Schedule,
20 Review the total case study showing
phases of P-D-C-A Cycle
P-D-C-A Cycle
21 Future Plan – next case-study Problem statement
22 Appreciation Letter, Thank people,
who helped you going out of way.
Thank judges and audience.

49. 49
PRESENTATION
• The presentation is done to make the audience understood the total case study.
• Speak at normal pace and adjust the presentation according to total time available.
• Regulate the slides show matching with the verbal presentation.
• Avoid capital letters except for headings.
• Use stick or electronic pointer to explain the slide or model.
• Hold slides with important points for some time adequate for reading by audience,
indicating the spot with pointer.
• All members on the stage should participate, not necessarily equally.
• Don’t obstruct the view of slide show. Stand accordingly.
• Speak to the mike looking towards audience.
• The answers should be short and to the point.
• Don’t try to argue or convince the judge. Agree to look into later.
• Agree to take care if any mistake was pointed out.
• Write down the script of presentation and speak after memorising the same.
• At the end summarise what you have presented.

50. 50
Short Presentation
1. Problem Statement with Target
2. Impact of the Problem with Data
3. Cause and Effect Diagram
4. Root Causes
5. Pareto Chart
6. Alternate Solutions
7. Accepted Solution
8. Tangible and Intangible Benefits

51. 52

52. 54
HUMAN PRINCIPLES
Recognition of achievement is very important people.
People like and feel a need to share their experience.
Group achievements have the effect of group bonding and
creating a sense of belonging.
Success breeds success. People are encouraged by
achievement and feel to equal or surpass their best.
People want to be listened to and feel important.
Everyone wants to have an opportunity for continuous
self development and self respect.
If you treat people like responsible human being, they are
likely to behave like them.

53. 55
WHY A TEAM
T TOGETHER
E EVERYONE
A ACHIEVES
M MORE

54. 56
BIG "Q" & SMALL "q"
The Japanese call product quality the small "q" and the
quality of the product including cost, delivery and service,
the big "Q".
WHY THE NAME QUALITY?
A higher degree of product quality, competitive cost,
committed delivery and good services, will result into
satisfied customers and repeat business, which in turn
will improve profitability, job security, and overall
prosperity of the Organisation. Hence the name
"QUALITY"

55. 57
Principles of variation
1. Every process is subjected to variation. Though it is
possible to minimise variation, it is impossible to eliminate it.
2. Variation should be understood over a period of time. The
behaviour of any process also must be understood over time.
No valid conclusion can be drawn about a process by
analysing a small sample size.
3. Variation is induced either by Random (common) causes or
Assignable (special) causes. Before initiating any action, we
need to understand if the variation is indicative of a real
change or it is simply a random variation, which is no
different from what has occurred in the past.
Variation, induced by many causes resulting in a small variation
in the output, is referred to as common cause variation
Variation, induced by one or a few causes resulting in a large
variation in the output, is commonly referred to as special
cause variation.

56. 58
Control charts
Dr.Walter A Shewhart developed the control chart. Control charts are
simple time series graphs or run charts. Three horizontal lines: the
central line is the average of the data (targeted mean). The upper and
lower control limits are statistically computed limits based on
historical data.
The data points within control limits are under the influence of
common cause variation, and points outside the control
limits may be under the influence of common causes or
the special causes.

57. 59
A n a l y s i s o f D a t a / C h a r t :
1 ) T h e r e a r e n o b r i c k s p r o d u c e d " o u t s i d e " t h e l i m i t s f ix e d b y t h e S u p e r v i s o r .
T h e r e f o r e , t h e P r e s s m a n w i l l a l l o w t h e p r e s s i n g s t o c o n t i n u e .
2 ) M o s t o f t h e B r i c k s p r o d u c e d a r e l a r g e r t h a n 7 5 m m .
Control Chart
75.2
75.4
75
75.3
74.9
75.4
75.2
75.3
75.1
6AM 7AM 8AM 9AM 10AM 11AM 12AM 1PM 2PM
Time
Thickness
75.5
74.5
Upper control limit
Lower control limit

58. 60
T r a n s f o r m i n g D a t a t o C o n t r o l C h a r t s
C o n s i d e r a P r e s s w h i c h is p r e s s i n g b r i c k s . T h e t h i c k n e s s i s r e q u ir e d t o b e 7 5 m m w it h
a g i v e n p l u s a n d m i n u s t o l e r a n c e s p e c if ie d b y t h e c u s t o m e r . A s t h e s e b r i c k s a r e
p r o d u c e d , t h e o p e r a t o r r a n d o m l y s e l e c t s a s a m p l e e v e r y h o u r , m e a s u r e s i t a n d e n t e r s
t h e d a t a i n t h e t a b l e b e l o w .
6 A M 7 A M 8AM 9 A M 1 0 A M 11AM 1 2 A M 1PM 2 P M
W i d t h 75.2 75.4 75.0 75.3 74.9 75.4 75.2 75.3 75.1
T h e S u p e r v i s o r h a s d e t e r m i n e d a s e t o f lim it s f o r t h e T H IC K N E S S . T h e s e lim i t s a r e
a t 7 4 .5 a n d 7 5 .5 m m .
T h e o p e r a t o r h a s b e e n i n s t r u c t e d t o s t o p t h e p r e s s a n d a l e r t t h e s u p e r v i s o r i f a n y
m e a s u r e m e n t s h o u l d g o " o u t s i d e " t h e s e l im i t s . If t h e m e a s u r e d v a l u e s s t a y w i t h i n
t h e s e li m i t s , t h e o p e r a t o r l e t s t h e p r o c e s s r u n ,
A b a s i c c o n t r o l c h a r t m a y b e d e v e l o p e d w i t h t h e d a t a i n t h e t a b l e a b o v e .