Quality Progress - January 2016 - (Page 35)
BACK TO BASICS
Separate the Vital Few
From the Trivial Many
A Pareto diagram can help you decide which improvement efforts to make first
by Melissa G. Hartman
Category of complaint
S E P T E M B E R
2 0 0 1
Pareto Diagram by Total Cost of Complaints
few beds special
W W W . A S Q . O R G
Pareto Diagram by Number of Complaints
Number of complaints
3. Gather data and place them
into one of the categories.
About Hotel Rooms
4. Enter the categories, counts and
cumulative frequency into a
Number of Cost of each
table or spreadsheet. This is a
Category of complaint
summary step that prepares the
data for the Pareto diagram.
Room not stocked
The data in Table 1 depict the
Room not ready
occurrence and cost of cusRoom too noisy
tomer complaints at a small
Room needs maintenance
Too few beds
hotel. The seven categories of
No special accommodations
complaints are in the first column, the number of complaints
in the most recent month is in
Calculate total cost by multiplying the
the second column, and the approxicost of each complaint by the number of
mate average cost of resolving each
occurrences. According to Figure 2, the
complaint is in the third column.
most costly complaints are the rooms are
5. Develop the diagram. Figure 1 shows
too noisy or are not ready when the guest
the categories of complaints in
arrives. This diagram requires a differdescending order. The number of
ent type of response from the one
complaints is on the left axis. A
indicated by Figure 1.
cumulative percentage distribution-
Pareto diagrams are useful in situathe line going upward from the first
tions where there are categorical data.
category-is scaled on the right axis.
The diagrams are easy to develop and
This shows the proportion of the
provide powerful insight into organitotal number of complaints accountzational problems.
ed for as each successive category is
6. Interpret the diagram. The most fre1. Joseph M. Juran, Juran on Leadership for
quent complaints shown in Figure 1
Quality (New York: The Free Press, 1989).
2. James R. Evans and William M. Lindsay, The
are that the room is not stocked or is
Management and Control of Quality (Cincinnati:
dirty. These two categories account
South-Western College Publishing, 1999).
for about 59% of the total com3. Nancy R. Tague, The Quality Toolbox
plaints. An appropriate action in
(Milwaukee: ASQ Quality Press, 1995).
response to this information might
be to investigate housekeeping pracMELISSA G. HARTMAN is assistant professor
tices and identify opportunities for
of management at Baker University School of
standardization and improvement.
Professional and Graduate Studies in Overland
However, if your goal is to reduce the
Park, KS. Hartman is an ASQ Fellow and certotal cost of complaints, a Pareto diagram
tified quality manager, quality engineer,
quality auditor and mechanical inspector. QP
can provide a different perspective.
Pareto diagrams graphically depict
categorical data. A Pareto diagram is a
bar graph, and each bar represents a
category. The bars are rank ordered in
descending order from left to right.
The bar on the left represents the category with the greatest value, and the
bar on the right the category with the
least value. The tallest bar is always on
the left and the shortest on the right.
Pareto diagrams are based on the
principle of separating the vital few
from the trivial many. This Pareto
principle was developed by Joseph
Juran, based on the work of Italian
economist Vilfredo Pareto (18481923).1, 2 Pareto determined 85% of the
wealth in Milan was owned by 15% of
the citizens. Similarly, Juran observed
that a majority of organizational effects
resulted from just a few causes.
Today, the Pareto principle implies
80% of process problems can be
accounted for by 20% of process factors. The premise behind the diagram
says process improvement efforts will
be more effective if the categories on
the left (the vital few) are addressed
first. The rank ordering of categories
simplifies detection of the vital few.
Follow these simple steps to construct a Pareto diagram:3
1. Decide which categories will be
used for grouping, such as the quantity of each type of lab test or
reasons for patient falls.
2. Decide how you will measure the
categories. Common measures
include the number of occurrences in
each category or total cost of the
occurrences in each category.
stocked few beds special
Category of complaint
January 2016 * QP 35
Table of Contents for the Digital Edition of Quality Progress - January 2016
According to Plan
Use Your Head
Stakeholder Management 101
All About Data
Eight Simple Steps
Which Six Sigma Metric Should I Use?
Turning ‘Who’ Into ‘How’
In the Beginning
Outputs and Outcomes
That’s So Random—Or Is It?
Improving a System
Putting It All on the Table
Know the Drill
It’s Fun To Work With an F-M-E-A
Solve Problems With Open Communication
Tell Me About It
Separate the Vital Few From the Trivial Many
To DMAIC or Not to DMAIC?
Breaking It Down
1 + 1 = Zero Defects
Curve Your Enthusiasm
Make a Choice
What Is a Fault Tree Analysis?
Successful Relationship Diagrams
The Benefits of PDCA
Return on Investment
The Art of Root Cause Analysis
Why Ask Why?
Get to the Root of It
Checks and Balances
Clearing SPC Hurdles
Supplier Selection and Maintenance
Building a Quality Team
Plan Experiments to Prevent Problems
Quality Progress - January 2016