Quality control is a process that is used to ensure a certain level of quality in a product or service. It might include whatever actions a business deems necessary to provide for the control and verification of certain characteristics of a product or service. Most often, it involves thoroughly examining and testing the quality of products or the results of services. The basic goal of this process is to ensure that the products or services that are provided meet specific requirements and characteristics, such as being dependable, satisfactory, safe and fiscally sound. Check sheet Control chart Histogram Ishikawa Diagram Pareto Chart Scatter diagram Flow chart

1. Quality Control Methods
Mohamed Sharique. V

2. What is Quality Control?
Quality control is a process that is used to ensure a certain
level of quality in a product or service. It might include whatever
actions a business deems necessary to provide for the control and
verification of certain characteristics of a product or service. Most
often, it involves thoroughly examining and testing the quality of
products or the results of services. The basic goal of this process is to
ensure that the products or services that are provided meet specific
requirements and characteristics, such as being dependable,
satisfactory, safe and fiscally sound.

3. • Manufacturers of food products often have employees who test the
finished products for taste and other qualities.
• Clothing manufacturers have workers inspect garments to ensure that
they are properly sewn.
• Service-oriented companies often have representatives who observe the
services being performed or who do follow-up checks to ensure that
everything was done properly.
Basic examples of Quality Control

4. When does Quality Control occur?
1. When raw materials are received prior to entering production.
2. Whilst products are going through the production process.
3. When products are finished - inspection or testing takes place before
products are despatched to customers.
4. Evaluating people. (Applicable with service-oriented companies.)

5. 7 Basic Tools of Quality
• Check sheet
• Control chart
• Histogram
• Ishikawa Diagram
• Pareto Chart
• Scatter diagram
• Flow chart

6. NEW 7 MANAGEMENT TOOLS

7. WHY THE NEW SET OF TOOLS
• To structure the brainstorming process
• Simplify
• Remove fear
• To help create a comfort fit (minimal
dependence on statistics)
• Improve penetration
• Increase application

8. LIST OF TOOLS
• Affinity Diagram
• Interrelationship diagraph
• Tree Diagram
• Matrix Diagrams
• Matrix Analysis
• PDPC, process decision program charts
• Arrow diagrams

9. AFFINITY DIAGRAM
Definition
An Affinity Diagram is a special type of
brainstorming process that is used for
organizing large groups of information into
meaningful categories. It helps us to clarify and
make sense of a large or complex problem

10. AFFINITY DIAGRAM
Process
• Record each idea on cards or notes
• Look for ideas that seem to be related
• Sort cards into groups until all cards have
been used.

11. AFFINITY DIAGRAM
Example
How to implement a process of continual
improvement throughout the organization?
Which causes of waiting time in the hospital
should we be working on?

12. AFFINITY DIAGRAM
Example

13. AFFINITY DIAGRAM
Example

14. INTER RELATIONSHIP DIAGRAPH
Definition
This tool displays all the interrelated
cause-and-effect relationships and
factors involved in a complex problem
and describes desired outcomes. The
process of creating an interrelationship
diagraph helps a group analyze the
natural links between different aspects
of a complex situation.
`

15. INTER RELATIONSHIP DIAGRAPH
Process
• Agree on the issue or question.
• Add a symbol to the diagram for every element involved in the issue.
• Compare each element to all others. Use an "influence" arrow to
connect related elements.
• The arrows should be drawn from the element that influences to the one
influenced.
• If two elements influence each other, the arrow should be drawn to
reflect the stronger influence.
• Count the arrows.
• The elements with the most outgoing arrows will be root causes or
drivers.
• The ones with the most incoming arrows will be key outcomes or results.
`

16. INTER RELATIONSHIP DIAGRAPH
Example
The quality issue is the potential causes or factors contributing
to late deliveries.

17. INTER RELATIONSHIP DIAGRAPH
Example

18. INTER RELATIONSHIP DIAGRAPH
Example
The inference is that Potential causes for late delivery
are:
• ‘Poor scheduling practices’ (6 outgoing arrows),
• ‘Late order from customer’ (5 outgoing arrows), and
• ‘Equipment breakdown (3 outgoing arrows).

19. TREE DIAGRAM
Definition
This tool is used to break down broad
categories into finer and finer levels of
detail. It can map levels of details of tasks
that are required to accomplish a goal or
task. It can be used to break down broad
general subjects into finer and finer levels
of detail. Developing the tree diagram
helps one move their thinking from
generalities to specifics.

20. TREE DIAGRAM
Process
• Develop a statement of the goal
• Ask a question that will lead you to the next level of detail.
• Brainstorm all possible answers. Write each idea in a line below. Show links
between the tiers with arrows.
• Do a “necessary and sufficient” check. Are all the items at this level
necessary for the one on the level above?
• Each of the new idea statements now becomes the subject: a goal,
objective or problem statement.
• Continue to turn each new idea into a subject statement and ask the
question, till you reach a root cause
• Do a “necessary and sufficient” check of the entire diagram. Are all the
items necessary for the objective?

21. TREE DIAGRAM
Example
The Pearl River, NY School District, a 2001 recipient of the Malcolm Baldrige
National Quality Award, uses a tree diagram to communicate how district-
wide goals are translated into sub-goals and individual projects. They call
this connected approach “The Golden Thread.”
The district has three fundamental goals. The first, to improve academic
performance, is partly shown in the figure below. District leaders have
identified two strategic objectives that, when accomplished, will lead to
improved academic performance: academic achievement and college
admissions.

22. TREE DIAGRAM
Example

23. MATRIX DIAGRAM
Definition
This tool shows the relationship
between items. At each intersection a
relationship is either absent or present.
It then gives information about the
relationship, such as its strength, the
roles played by various individuals or
measurements. Six differently shaped
matrices are possible: L, T, Y, X, C, R and
roof-shaped, depending on how many
groups must be compared.

24. MATRIX DIAGRAM
Example
A personnel department wanted to improve social activity within the company in
order to increase loyalty levels. A theory was put forwards that soft-skills training
contributed significantly towards this in-house socializing. The personnel manager
consequently decided to use a Matrix Diagram to investigate this. The steps taken
were:
Objective: Investigate effect of soft-skills training on social activity.
Matrix: T-matrix, with people on main stem, in-house training courses to left,
attendance of social clubs to right, plus an extra column for years of service.
Comparison: In-house training - tick for attendance within last three years; social
clubs - three bands corresponding to under 30%, 30% to 70% and over 70%
attendance in the same period.

25. MATRIX DIAGRAM
Example

26. MATRIX DIAGRAM
Example
The resultant matrix, showed that people with higher levels
of social training also tended to be more committed
members of social clubs. It was also noticed that there
seemed to be a particular increase in commitment after
going on the team-building course. The length of service
showed no particular pattern.
As a result, the training was expanded, and people were
given more encouragement to attend (particularly the
team-building course). This resulted in a steady increase in
social activity and a reduction in attrition rates.

27. PRIORITISATION MATRIX
Definition
This tool is used to prioritize items and
describe them in terms of weighted criteria.
It uses a combination of tree and matrix
diagramming techniques to do a pair-wise
evaluation of items and to narrow down
options to the most desired or most
effective.

28. PRIORITISATION MATRIX
Example
Problem
To identify the most important factors effecting
motivation in a team

29. PRIORITISATION MATRIX
Example

30. PRIORITISATION MATRIX
Example
Pay and work overload, as the highest scoring
motivational problems, were selected for carrying
forward for further investigation. As a result of
consequent work in the project, the pay structure for
certain grades was revised and training on job
scheduling was introduced. In the following year, the
survey improved in these areas by 2 and 3 points,
respectively.

31. PDPC
Definition
A useful way of planning is to break down tasks
into a hierarchy, using a Tree Diagram. The PDPC
extends the tree diagram a couple of levels to
identify risks and countermeasures for the
bottom level tasks. Different shaped boxes are
used to highlight risks and identify possible
countermeasures (often shown as 'clouds' to
indicate their uncertain nature). The PDPC is
similar to the Failure Modes and Effects Analysis
(FMEA) in that both identify risks, consequences
of failure, and contingency actions; the FMEA
also rates relative risk levels for each potential
failure point.

32. PDPC
Process
From the bottom level of some activity box, the PDPC adds
levels for:
•identifying what can go wrong (failure mode or risks)
•consequences of that failure (effect or consequence)
•possible countermeasures (risk mitigation action plan)

33. PDPC
Example
A dress production team at a clothes manufacturer was
improving the cutting-out process in order to minimize
material wastage. They decided to use PDPC on the
work breakdown structure to identify potential
problems and ways of avoiding them.
As the most expensive element is the material itself,
they defined a significant risk as, 'Anything that might
cause the cut cloth to be ruined', and viable
countermeasures as, 'Anything that will reduce the risk,
and which costs less than 100 pieces of cloth' .

34. PDPC
Example

35. PDPC
Example
As a result of this, the cutting was tested on cheaper
material, resulting in the material clamp being
redesigned to prevent drag, a start notch provided for
the cutter and the general area being inspected for
sharp corners to minimize snag problems. The cutting
operator was involved in the PDPC process and the
subsequent tests, resulting in her fully understanding
the process. The final cutting process thereafter ran
very smoothly with very little error.

36. ACTIVITY NETWORK DIAGRAM
Definition
This tool is used to plan the appropriate
sequence or schedule for a set of tasks and
related subtasks. It is used when subtasks
must occur in parallel. The diagram enables
one to determine the critical path (longest
sequence of tasks).
Two Types
•Arrow on Node
•Arrow on Arrow

37. ACTIVITY NETWORK DIAGRAM
Process
Drawing the Network
List all the necessary tasks in the project or process. One convenient method is to
write each task on the top half of a card or sticky note. Across the middle of the
card, draw a horizontal arrow pointing right.
Determine the correct sequence of the tasks. Do this by asking three questions for
each task:
Which tasks must happen before this one can begin?
Which tasks can be done at the same time as this one?
Which tasks should happen immediately after this one?
It can be useful to create a table with four columns —prior tasks, this task,
simultaneous tasks, following tasks.

38. ACTIVITY NETWORK DIAGRAM
Process
First do a forward pass to note down the duration and the
Earliest finish and start times
Then a backward pass is done to fill in the Latest finish, start
and total float times

39. ACTIVITY NETWORK DIAGRAM
Example
ActivityActivity Time (days)Time (days)
ImmediateImmediate
PredecessorsPredecessors
AA 22 --
BB 77 --
CC 44 AA
DD 33 AA
EE 22 B,CB,C
FF 33 D,ED,E

40. ACTIVITY NETWORK DIAGRAM
Process float time and critical path
0 2 2
1 1 3
A
0 7 7
0 0 7
B
2 4 6
3 1 7
C
2 3 5
6 4 9
D
7 2 9
7 0 9
E
9 3 12
9 0 12
F

41. Some problems concerning Quality Control:
• The inspection process does not add any "value". If there
were any guarantees that no defective output would be
produced, then there would be no need for an inspection
process in the first place.
• Inspection is costly, in terms of both tangible and intangible
costs. For example, materials, labour, time, employee
morale, customer goodwill, lost sales.
• It is sometimes done too late in the production process.
This often results in defective or non-acceptable goods
actually being received by the customer

42. • It is usually done by the wrong people - e.g. by a separate
"quality control inspection team" rather than by the workers
themselves
• Inspection is often not compatible with more modern
production techniques (e.g. "Just in Time Manufacturing")
which do not allow time for much (if any) inspection.
• There is often disagreement as to what constitutes a "quality
product". For example, to meet quotas, inspectors may
approve goods that don't meet 100% conformance, giving the
message to workers that it doesn't matter if their work is a bit
sloppy. Or one quality control inspector may follow different
procedures from another, or use different measurements.

43. Difference between Quality Control &
Quality Assurance
• Though the two are similar, but there are some basic
differences. Quality control is concerned with examining the
product or service — the end result - and quality assurance is
concerned with examining the process that leads to the end
result.
• A company would use quality assurance to ensure that a
product is manufactured in the right way, thereby reducing or
eliminating potential problems with the quality of the final
product.

44. "Inspection with the aim of finding the bad ones and
throwing them out is too late, ineffective, costly.
Quality comes not from inspection but from
improvement of the process."
- W. Edwards Deming
“Any tool is a weapon if you hold it right”
- Ani DiFranco

45. Thank you