Quality Tools Homework Assignment

Every important activity in a value stream should be measured. A run chart is common tool used to
monitor these measurements over time. A run chart is alternatively called a time series chart or a trend
chart. A run chart is basically a Statistical Process Control Chart without the upper and lower limits. For a
run chart, the value stream measurement is displayed according to the Y axis and the time/sequence is
displayed on the X axis.

A histogram is a tool to graphically display the frequency of the value stream measurements without
regard for time. For a histogram, the value stream measurements are displayed on the X axis and the
frequency of the measurements, according to dimensional categories, are displayed on the Y axis. The
description of histogram on pages 63 and 65 in the text is misleading. These descriptions are more akin
to a bar chart, or when the categories are organized from most frequent to least frequent, to a pareto
chart. A correct description of histogram, also called a frequency distribution chart, can be found at
http://www.socialresearchmethods.net/kb/statdesc.php
, under the subheading section title 
The
Distribution
, and including Tables 1 and 2.

When analysis of the values stream measurements using a run chart and a histogram indicate that the
performance is deficient, then the potential causes for “gaps” in performance can be analyzed with a
Cause-and-Effect Diagram.

When data are collected for these potential causes (or categories) of poor performance, then the data
can be displayed with a Pareto chart, visually indicating the cause/categories by number or percentage,
with the cause/category with the greatest number/frequency in the far left column and the
cause/category with the least number/percentage in the far right column.

Choosing some process activity which is measured, I am asking you to complete three out of the four
following assignment deliverables. You choose which 3 to complete. Computer generated or hand draw
submissions are accepted.

1. 
Create a run chart and make a comment about the performance.
2. 
Create a histogram and make a comment about the performance.
3. 
Brainstorm the potential causes of deficient performance using a cause-and-effect diagram, and

make a comment about the results of the analysis.
4. 
Create a pareto chart based upon causes/categories of performance deficiency, and make a
comment about the results of the analysis.

Your resources may include your own personal experience or first-hand observation, your interview of
someone with personal experience or first-hand observation, an article, case study, or web site. Do not
cut and paste from any source, except for brief quotations that are properly cited.