2013.10.22

By ML

SPC - 7 BASIC TOOLS

STATISTICAL PROCESS

CONTROL (SPC)-7 BASIC TOOLS

1. Check Sheet

2. Stratification

3. Scatter Diagram

4. Histogram

5. Pareto Chart

6. Control Chart

7. Cause and Effect Diagram

CHECK SHEET

Data record

Develop a matrix for data collection.

Checklist

To list all necessary items and their status.

STRATIFICATION ANALYSIS

Stratification Variables

Stratification Tables Graph chart Advanced

chart

To group your data by a stratification variable.

Summary Statistics by Groups or Levels of an Output. „ Common Summary Statistics include: „ Mean, Standard Deviation, Sums, Counts

Bar Graphs / Pie Charts / Flow Chart / Contingency table.

Stratify distributions using multiple histograms or multiple box plots

…X and Y

EXPLAIN THE RELATIONSHIP

BETWEEN..

SCATTER DIAGRAM

HISTOGRAM

Normal manufacturing process, normal quality

Data from difference sources.

Limitation

HISTOGRAM VS. BAR GRAPH

Histogram

Bar chart (bar graph)

Normal manufacturing process, normal quality

Size, shape and the density of interval.

Height

The distribution of research subject.

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.

Check Sheet A systematic and constantly, data record

collection.

Stratification Category the cause of variation, distinct the

difference.

Scatter

Diagram

To find out the relationship of two variables.

Histogram Represent tabulated frequency, often for

density estimation.

Problem identification

Cause and effect

relationship

Problem

identification

Cause and effect

relationship

Cause and effect

relationship

Problem

identification

we found the process in red circle is the major problem.

we noticed that its not a normal distribution thru histogram chart.

Clarify with the issue ‘X’, does it associate with factor ‘Y’;

the other way is to stratify the process which in red circle.

REVIEW THE 4 BASIC TOOLS

CAUSE AND EFFECT DIAGRAM

Measurement Materials Method

Analytical procedure

Sampling

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.

ADDRESS YOUR CONCLUSION Follow MECE Principle mutually exclusive and collectively exhaustive

East West South North

direction

East West North

East South

West North

Blue

Seattle

East ← South ↓

West→ North ↑

Blue

Seattle

Summarizing

East west south north

Find what’ve been missing

Grouping ← → ↑