# PE GS tory by A343R5

VIEWS: 0 PAGES: 14

• pg 1
```									A QUALITY IMPROVEMENT “STORY”
PACIFIC ELECTRIC & GAS (PE&G)
To illustrate a systematic approach to Quality Improvement,
we will describe the activities of a quality improvement team
within PE&G’s Haasville District.

Our goal is to illustrate the following:
 The need to have a quantifiable measure of quality.
 The need for the quantifiable measure of quality to be customer
oriented.
 How to use a Pareto Chart to select which of a problem’s “root
causes” to improve.
 How to use a Fishbone Diagram to summarize a problem’s root
causes.
 The importance of Knowledge Transfer and Learning.                1
STEP 1: Identify a Quantifiable Measure
of Quality that is Customer Oriented
The Haasville team first considers a goal of
Provide Reliable Electric Service.
Why is this goal inappropriate?
“If you don’t measure it, you cannot improve it.”
“In God we trust. All others bring data.”
Next, the Haasville team considers measuring its service
quality as the
Number of Power Outages per Year.
Although this measure is quantifiable, why is it NOT
customer oriented?                                         2
Finally, the Haasville team decides that its measure of service
quality will be the SERVICE UNAVAILABILITY INDEX.

EXHIBIT 1: Summary of Computation SUI
EXHIBIT 1: SERVICE UNAVAILABILITY INDEX
Data for Most Recent Calendar Year
Outage's
Number of Outage's
Affected    Duration
Outage    Customers in Minutes      Product       Outage's
Number        (N)        (D)         (NxD)         Cause
1         500         60          30,000    Birds/Animals
2         900          5           4,500     Lightening
3         300         15           4,500        Wind
---         ---        ---           ---           ---
---         ---        ---           ---           ---
---         ---        ---           ---           ---
150        700         30          21,000     Lightening
SUI = Sum of Products =   1,800,000

SUI is both quantifiable and customer oriented.                     3
Having identified SUI as its measure of service quality, the Haasville
team sets a goal of reducing SUI. The team examines each POWER
OUTGAGE REPORT (POR). For each power outage, the POR
includes:
 Time power went out and time it was restored,
 Number of customers affected,
 Cause of outage (if known) from a list of 35 possible causes.
Using the PORs, the team identifies the root causes of power
outages and summarizes them with the table below:
EXHIBIT 2: Summary of Root Causes

Number of
Root Cause             Occurrences
Lightening                  32
Birds/Animals                27
Wind                     24
Construction                 22
Vehicles                  17
Unknown and Other               15
Trees                     9
Equipment Failure               4
Column Sum =            150
4
What should the Haasville team do next?
The problem with Exhibit 2 is that it does not display the impact each root
cause has on SUI. Exhibit 3 below displays for each root cause both the
number of occurrences and the contribution to SUI.
EXHIBIT 3: Extended Summary of Root Causes

Number of    Contribution
Root Cause        Occurrences      to SUI
Lightening             32         315,000
Birds/Animals           27         126,000
Wind                24         225,000
Construction            22         180,000
Vehicles             17         540,000
Unknown and Other          15          45,000
Trees                9         360,000
Equipment Failure          4           9,000
Column Sum =       150        1,800,000

Although “Lightening” is #1 in terms of the number of occurrences,
“Vehicles” is #1 in terms of its contribution to SUI.

The Haasville team constructs the Pareto Chart in Exhibit 4 on the next
page. The Pareto Chart displays the root causes of outages in decreasing
order of their contribution to SUI.

NOTE: To construct within Excel a Pareto Chart similar to Exhibit 4, start
the Chart Wizard, click in Step 1 on Custom Types, and select Line-
Column on 2 Axes.                                                             5
EXHIBIT 4: Pareto Chart for Root Causes of All Outages
600,000                                                                                                                    100%
540,000
550,000                                                                                                                    90%
500,000
80%
450,000
Contribution to SUI

70%
400,000
360,000
350,000                                                                                                                    60%
315,000
Contribution to SUI
300,000                                                                                                                    50%
Percent of Total
250,000                                         225,000                                                                    40%
200,000                                                         180,000
30%
150,000                                                                        126,000
20%
100,000
45,000   10%
50,000
9,000
0                                                                                                                     0%

s
s

re
s

d

n
g

er
al
le

ee

in
in

tio

lu

th
m
c

W
en
Tr

ai
c

O
hi

ni
ru

tF
t
Ve

&
gh

A
st

s/

en

n
Li

on

w
ird

m

no
C

ip
B

nk
u
Eq

U
Root Cause

What should the Haasville team do next?                                                                                                         6
STEP 2: Analyze root causes of vehicle-
related outages and determine which one
to attack.

Using the PORs that were vehicle-related, the Haasville
team constructs the FISHBONE DIAGRAM in Exhibit 5 on
the next page. The Fishbone Diagram organizes the root
causes of a vehicle-related outage.

NOTE: To construct within Excel a Fishbone Diagram
similar to Exhibit 5, first display the Drawing toolbar by
using the menu selection View, Toolbars, Drawing. Then,
to draw the arrow-tipped lines, click on the toolbars arrow-
tipped line icon.

7
EXHIBIT 5
FISHBONE DIAGRAM (CAUSE & EFFECT DIAGRAM) FOR OUTAGES CAUSED BY VEHICLES

MAN
High Speed
Failure to Yield
Incorrect Sag
Driver Fell Asleep
Construction Equipment
l
ho
s

d
ug

co
re
Dr

Al
Ti

OUTAGES CAUSED
BY VEHICLES
Dark                           Pole on Outside of Curve

Rain                                                                     Clearance Too Low

Heavy Traffic

Wet Surface
Pole Too Close to Road

ENVIRONMENT                                               METHODS

How should the Haasville team determine which root cause
to attack first?                                                                                                                                      8
The Haasville team next constructs the Pareto Chart in
Exhibit 6 on the next page. The Pareto Chart displays root
causes of vehicle-related outages in decreasing order of
their contribution to SUI.

Although “Poles on Outside of Curve” is not necessarily #1
in terms of number of occurrences, it is #1 in terms of its
contribution to SUI.

So, the Haasville team chooses to attack the root cause
“Poles on Outside of Curve”.

9
EXHIBIT 6: Pareto Chart for Root Causes of Vehicle-Related Outages

200,000                                                                                        100%
190,000

180,000                                                                                        90%

160,000
160,000                                                                                        80%

140,000                                                                                        70%
Contribution to SUI

120,000                                    115,000                                             60%
Contribution to SUI
100,000                                                                                        50%    Percent of Total

80,000                                                                                        40%

60,000                                                                                        30%
50,000

40,000                                                                                        20%

20,000                                                                               15,000   10%
10,000

0                                                                                         0%
Pole on Outside Clearance Too   Driver Fell   Pole Too Close Construction   Other
of Curve          Low         Asleep          To Road      Equipment

Root Cause
10
STEP 3: Identify alternative
countermeasures that will mitigate the
root cause, and select one of these
countermeasures to implement.
The Haasville team uses BRAINSTORMING to develop
the following list of 11 alternative countermeasures:
   Relocate pole by moving it further back.
   Install barricade (doughnut) around pole.
   Move wires underground.
   Relocate pole to inside of curve.
   Install caution lights.
   Reduce speed limit.
   Install speed bumps on curve of road.
   Install reflectors on curbs at curve.
   Replace pole with break-away pole.
   Increase span between poles (i.e., decrease number of poles).
11
   Replace pole with stronger pole.
The Haasville team uses MULTIVOTING to reduce the entire
list of 11 countermeasures to 3-5 countermeasures. (On the
first vote, each team member can vote for any number of
countermeasures. In any subsequent vote, each team
member can vote for at most one-half the remaining
countermeasures. The vote continues until the list of
countermeasures is reduced to 3-5 items.)

Using Multivoting, the Haasville team reduces the list of
countermeasures to:
A.   Relocate pole by moving it further back.
B.   Relocate pole to inside of curve.
C.   Install speed bumps on curve of road.
D.   Install reflectors on curbs at curve.

To evaluate the four alternatives, the Haasville team selects
the following criteria:
1. Cost to Implement
2. Percentage of Problem Solved                                 12
3. External Assistance Required
To assist in the selection of the “best” of the four remaining
countermeasures, the Haasville team uses a technique for
choosing the “best” from a set of options that have each
been evaluated against a set of criteria. (One such
technique is Prioritization Matrices.)

After using Prioritization Matrices or a similar technique,
the Haasville team selects the following countermeasure:
Relocate poles currently located on outside of curve to
inside of curve.

How should the Haasville team decide the order in
which the poles should be relocated?

13
STEP 4: If necessary, repeat Step 2 and/or
Step 3, this time attacking another root
cause of vehicle-related outages in specific
or outages in general.

STEP 5: Prevent the problem and its root
cause from recurring.
To prevent future problems with vehicle-related outages, the
Haasville team designs a new process for locating new poles.
Furthermore, the Haasville team takes steps to ensure that this
new process is transferred to all of PE&G’s districts.

STEP 6: Summarize lessons learned.
The Haasville team answers the questions:
 What did we do well?
 What did we not so well?                                    14
 What could we do differently?

```
To top