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lubrication

roughing

tool wear

tool angle

location

cutting

speed

psi

Bore

Counter Sink

Chamfer

Unload

setup

tool

wear

wear

speed

centering

centering

check

• When considering CAUSES, there are two main types, assignable and chance. chance - normal, or natural variations that occur in a system (e.g. dice)

assignable - controllable parameters such as material, process parameters, operator skill, etc.

6.2 PARETO DIAGRAM

•After the CE diagram is constructed we can start to trace the cause of problems.

•Assume

1.We have collected data from defects on the factory floor.

2.We have identified the causes of each of the defects (could also use problems, type of problems, etc)

e.g. bad photocopies

Frequency	Defect
12	Paper Jam
1	Toner falls off
5	too light
3	Others

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3. We can rank the list)

e.g. bad photocopies

Frequency	Defect
12	Paper Jam
5	Too light
1	toner falls off
3	Others

4. Draw the graph (** This is a Pareto diagram)

12

freq.

5

3

1

			ne		othe
paper		too
			t
		light	o		r
	jam
			all
			r		s
			f
				s
				o
				f
				f

5. Tackle the problem on the left first. Paper jams are the most significant problem that comes up.

6.3 MATRIX ANALYSIS

• It is also possible to use the concept in the Pareto Diagram, in a setting with multiple processes.

1. Take data concerning quality.