Statistical Process Control (SPC) Tools - 7 Basic Tools

1. SPC - 7 BASIC TOOLS
2013.10.22
By ML

2. STATISTICAL PROCESS
CONTROL (SPC)-7 BASIC TOOLS
1.
2.
3.
4.
5.
6.
7.
Check Sheet
Stratification
Scatter Diagram
Histogram
Pareto Chart
Control Chart
Cause and Effect
Diagram

3. CHECK SHEET
Data record
Checklist
Develop a matrix
for data collection.
To list all necessary
items and their
status.

4. STRATIFICATION ANALYSIS
Stratification
Variables
To group your
data by a
stratification
variable.
Stratification
Tables
Summary
Statistics by
Groups or Levels
of an Output. „
Common
Summary
Statistics include:
„Mean, Standard
Deviation, Sums,
Counts
Graph chart
Bar Graphs /
Pie Charts /
Flow Chart /
Contingency
table.
Advanced
chart
Stratify
distributions
using multiple
histograms or
multiple box
plots

5. SCATTER DIAGRAM
EXPLAIN THE RELATIONSHIP
BETWEEN..
…X and Y

6. HISTOGRAM
Normal manufacturing
process, normal quality
Limitation
Data from
difference sources.

7. HISTOGRAM VS. BAR GRAPH
Histogram
Size, shape and
the density of
interval.
Normal manufacturing
process, normal quality
Bar chart (bar graph)
Height
The distribution of
research subject.

8. CREATING HISTOGRAM
1. Collecting input data (n>50).
2. Define K (base on sampling size, density of the bin, narrow the
interval)
Either the experience or use the formula K=1+3.32*log(n)
3. Define I
the Range : R=Xmax – Xmin
i= R/ K (take the odd number)
4. Bin range
L = Xmin-(unit/2), U=L+I …apply to other number, till > Xmax
5. On the Tools menu, click Data Analysis.
6. In the Analysis Tools box, click Histogram, and then click OK.

9. REVIEW THE 4 BASIC TOOLS
Check Sheet
A systematic and constantly, data record
collection.
Stratification
Category the cause of variation, distinct the
difference.
Cause and effect
relationship
Scatter
Diagram
To find out the relationship of two variables.
Cause and effect
relationship
Histogram
Represent tabulated frequency, often for
density estimation.
Problem identification
Problem
identification
Problem
identification
Cause and effect
relationship
 we found the process in red circle is  Clarify with the issue ‘X’, does it
associate with factor ‘Y’;
the major problem.
 the other way is to stratify the process
 we noticed that its not a normal
which in red circle.
distribution thru histogram chart.

10. CAUSE AND EFFECT DIAGRAM
Measurement
Materials
Method
Analytical procedure
Sampling

11. REVIEW THE OTHER 3 BASIC TOOLS
Pareto Chart
80-20 rule.
Control Chart
With comparing lines, to find and correct
the process variation when unpredictable
(out of control).
Cause and Effect
Diagram
The fishbone diagram identifies many
possible causes for an effect or problem. It
can be used to structure a brainstorming
session. It immediately sorts ideas into useful
categories.

12. ADDRESS YOUR CONCLUSION
Follow MECE Principle
mutually exclusive and collectively exhaustive
South
East
East
North
Seattle
East ←
→
↑
Grouping
Find what’ve been missing
East
South ↓
North ↑
Seattle
West
North
←
Blue
West
Blue
west
south
north
direction
Summarizing
West→
East
West
South
North