six sigma project: garbage collection

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Lean Six Sigma
Reducing Missed Garbage Pickups
Dawn Ritchie, Solid Waste Manager
Project Description
Problem
Statement:
Missed garbage pickups result in
increased costs and dissatisfied
customers
Objective:
Decrease missed garbage pickups
by fifty percent
Benefits
Benefits to the City
•
Improved Customer Service
•
Enhanced Relationship with Contractor, National Serv-all (NSA)
•
Potential Savings on Next Contract with Decreased Tonnage Rates
Benefits to the NSA
•
Improved Customer Service
• Decreased Costs
• Enhanced Relationship with the City
• Improved Driver Training
•
Potential Productivity Improvement from
Drivers/Collectors
Benefits to the Customer
• Improved Pickup Timeliness
• Increased Confidence and Satisfaction with Service
• Potential Cost Savings on New Contract
• Punctual Friday Pickups on New Contract
Project Team
Black Belt:
Dawn Ritchie
Champion:
Ted Rhinehart
Team Members:
Matt Gratz, City Solid Waste
Angela Lewis, NSA
Bob Young, NSA
Mike Welch, NSA
Definition and Costs of the Y
Y=
Validated or Legitimate Missed Garbage
Pickups
Y = f(x1,x2,x3,…,xk)
Costs
of Y=
The costs of the Y include
dissatisfaction and inconvenience for
customers and increased costs in fuel
and labor.
Defect Theories
• Driver Training - doesn’t return to where he
previously stopped
• Driver Experience
• Route Knowledge -miss entire street/alley
• Route Problems
• alley on side load route
• house in commercial area
• customer has no access to the alley
Why Defects?
• Environmental Factors
• ice/snow/weather
• alley cave-in
• Obstacles
•
•
•
•
road or alley closed
alley overgrown with brush
car parked in front of garbage
garbage hidden by bush, fence, garage/bldg
Project Objectives
• Special assist pickup
• Behavior/attitude of driver
–
–
–
–
in a hurry
carelessness
goes home early without finishing route
grudge towards homeowner
X’s
Process Chart
X’s
Staffing, equipment,
fuel, maps, weather,
traffic, construction,
pit stops, injury, trash,
obstacles, experience,
training, helper, route
knowledge, routing,
attitude, day of week,
assist pickup, set out
site, length of route,
mistake/error, time of
year, accidents
Prep for Work
Do Work
Y’s
cost of labor, cost of
fuel, depreciation
accidents, arrival at
route, employment,
customer complaints
calls, rerouting, good
pickup, discipline,
dissatisfaction,
sanitation/health,
corrective action,
evaluation, termination
Cause and Effect Matrix
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
7
9
1
2
3
4
5
training
attitude
equipment
assist pickup
obstacles
temperature
traffic
construction
weather
mistake/error
time of year
route length
illness/injury
staffing
alley/curb
staffing
6
7
8
9
10
11
12
13
14
15
9
9
9
9
9
360
9
9
9
3
9
3
3
3
3
3
3
3
3
3
1
1
9
9
3
9
3
3
3
3
3
3
3
3
1
1
3
3
9
9
3
9
3
3
3
3
3
3
3
3
1
1
3
3
9
3
9
1
3
3
3
3
3
3
3
3
3
3
1
3
9
9
9
3
3
3
3
3
3
3
3
3
3
3
3
1
360
318
276
190
180
120
120
120
120
120
120
120
92
92
86
82
9 9 9 9 9
9 9 9 3 9
9 3 3 9 9
do work
do work
do work
do work
do work
do work
do work
do work
do work
do work
do work
do work
do work
do work
do work
prep for work
didn't leave a
mess
6
9 9 9 9 9
Process Step Process Inputs
experience
do work
training
attitude
equipment
8
safety
experience
10
put lid back
Rating of
Importance to
Customer
retrieved
garbage
put can back
Cause and Effect
Matrix
360
Total
360
318
276
Data Collection Sheet
Six S igma P roject:
Improv ing Custo me r Se rvice by Reduc ing Misses
Data Collectio n S heet
Data o n Garba ge M iss
(C ity o f Fort Wa yne misse s o nly):
Name ______________________________
P ho ne number
___________________
Address ________ ___________________________________
Day of Colle ctio n:
Place of Co lle ctio n:
Mo n
Tues
Alle y
Enviro nme ntal Facto rs :
Wed
or
Ice
Curb
S now
Thur
Obstacle s:
Road/a lle y c losed
(c irc le o ne)
(c irc le o ne)
Se ve re Wea ther
High Te mp /Humid ity
N/A
F ri
Ra iny
S unny
C lo ud y
Othe r ____________________
(c irc le o ne)
O vergrown b rush in a lle y
Garba ge hidde n b y b ush/gara ge /fe nce
Ve hic le parked in the wa y o f the garba ge
Other
___________ __________________________________
N/A
(c irc le o ne)
Elde rly/Handica p S pe cial Assist Pick up:
Route Pro ble m:
YES
Alle y o n a s ide load ro ute
NO
(circ le o ne)
Ho use in a co mmerc ia l zo ne
Custo mer doe s not ha ve ac cess to the a lle y
Other ____________ _____________________________
N/A
Co mme nts
(c irc le o ne)
_____________________________________________________________
________________________________________________________________________
Data Collection Sheet
Six Sigma P roject:
Improv ing Custo me r Se rvice by Reduc ing Misses
Data Collectio n Sheet
Information to be provided by Mike Welch:
Route Number
Dri ver Name
____________
(Rte. Nu mber 1 – 18)
___________________________________
Hel per Name ____________________________________
Dri ver Tr aining
YES
NO
(circle one)
Hel per Tr aining
YES
NO
(c irc le one)
Dri ver Experience wi th Nati onal Ser v-all
_________________ yrs .
____________________ mos .
_________________ days , if not more than one month
Hel per Experience with National Ser v-all
__________________ yrs . ____________________ mos .
_____________________ days , if not mo re than one month
Dri ver Knowle dge of Route/ How long has dri ver bee n on the route?
____________________ yrs
____________________ mos
____________________ days ,
if les s than one month
Pareto Chart-Day
Pareto Chart for Day
100
70
60
80
60
40
30
40
20
20
10
0
Defect
Count
Perc ent
Cum %
0
M
Th
14
12
10
18.7
70.7
16.0
86.7
13.3
100.0
T
F
W
22
17
29.3
29.3
22.7
52.0
Percent
Count
50
Pareto Chart-Environment
Pareto Chart for Env
100
70
60
80
60
40
30
40
20
20
10
0
Defect
Count
Perc ent
Cum %
0
C
s
er
Oth
S
NA
R
42
14
9
8
2
56.0
56.0
18.7
74.7
12.0
86.7
10.7
97.3
2.7
100.0
Percent
Count
50
Dotplot for D Know
Dotplot for D know
0
100
200
D know
300
Pareto Chart-Driver
Pareto Chart for Driver
100
70
60
80
60
40
30
40
20
20
10
0
Defect
Count
Perc ent
Cum %
0
ter
s
d
n
r
rt
ex on
o
e
d
a
d
h
wn i a m i t h
th
in
er
s
s
y
er
n s Po rt o l a n en h
in
t s m i th Ru s
B ro
l
mi
u t Ca rt oo d a n k
ze e p h
s
h
o
a
i
m
S
c
a
o
R
R
P
W
S
rd
W
S
A
B
e
h
er
ff J in c e c o t
e
ce
ry
ill
llis on a
e h ri s l y de
el
us
k W im
llV a n S
Oth
e
v
n
r
B
E
n
o
rc
r
i
J
S
y
C
C
J
T
W
Pr
D a e rr a
La
Le
Ma
Ma
B ri
Wa
T
10
9
8
7
7
4
3
3
3
3
2
2
2
2
2
2
2
1
3
13
12
11
9
9
5
4
4
4
4
3
3
3
3
3
3
3
1
4
13
25
36
45
55
60
64
68
72
76
79
81
84
87
89
92
95
96 100
Percent
Count
50
Pareto Chart-Helper
40
100
30
80
60
20
40
10
20
0
Defect
Count
Perc ent
Cum %
0
T
p.
em
n
To
y
r
we
Bro
l
Wi
ia m
o
Mo
e
r
Ro
e
yc
aw
Sh
g
Gre
l
Ha
H
ee
Fr
n
a
e rm
21
7
4
3
2
2
53.8
53.8
17.9
71.8
10.3
82.1
7.7
89.7
5.1
94.9
5.1
100.0
n
ma
Percent
Count
Pareto Chart for Helper
Pareto Chart-A/C
Pareto Chart for A/C
100
70
60
80
60
40
30
40
20
20
10
0
Defect
Count
Perc ent
Cum %
0
C
48
64.0
64.0
A
25
33.3
97.3
er
Oth
2
2.7
100.0
s
Percent
Count
50
FMEA Results-Key Problems
•
•
•
•
•
•
•
•
•
•
•
•
Hurried Collectors
Worker Turnover
Fatigued Workers
Distractions/Daydreaming
Poor Attitude
Lack of Communication
Normal Equipment Failure
Wear-and-Tear on Trucks
Shortage of Labor
Lack of Time
Lack of Money
Inadequate Route Information
Current Controls
• Training
• Safety Meetings
• VCR Report
• PM
Improvement Ideas
•
•
•
•
•
•
•
•
•
•
Improve Hiring Practices
Pay Hourly
Provide Additional Training
Launch Probation Period
Increase Route Supervision
Resend Drivers to Collect Misses
Update Maps
Increase Money for Training and PM
Shorten Routes
Provide Better Incentives
Key Problem Areas
1.
2.
3.
4.
Hurried Workers
Fatigued Workers
Worker Turnover
Lack of Communication
Key Problem-Hurried Workers
• Current Controls
–
–
–
–
–
–
Balanced Routes
Teamwork Policy
Management Change
Increased Coaching
Provide Appropriate Tools
Reduced Worker Turnover
• Improvement Ideas
–
–
–
–
Reduce Route Size
Pay Hourly
Adjust Incentives
Provide More Training
Key Problem-Fatigued Workers
• Current controls
– Increased Employees
– Improved PM
– Changed Route Schedule
• Improvement
– Developed an 18 ton limit
on one-man routes
– Increased Helpers
– Decreased Route Size
– Modified Pay Structure
Key Problem-Worker Turnover
• Current controls
–
–
–
–
–
–
–
–
–
–
–
–
–
Employee Appreciation Day
ask them for their input
show concern
communication of goals and
benefits
improve workplace environment
Employee of the Month and Year
Bonus check
better equipment maintenance
shorten workday
safety bonuses
shoe allowance
Christmas party
explain whole picture/more
communication
• Improvement
–
–
–
–
–
better pay
more benefits
more helpers
limit route size
continue to find
ways to show
appreciation
Key Problem- Lack of Communication
• Current controls
– keep the workers
informed
– Hold Safety
Meetings
– New Trainer
– special assist
pickups on route
sheet
– Improved dispatch
• Improvement
– Add Frequent Misses
to Route Sheets
– Schedule Weekly Staff
Meetings
– Receive Employee
Feedback
– really push the goals of
the company
– Communicate
Performance Measures
Product:
Key Contact:
Phone:
Process
Trash pickup
Trash pickup
Trash pickup
Trash pickup
Garbage pickup
Dawn Ritchie
427-1345
Process Step
Do work
Prep for work
Do work
Do work
Core Team:
Output
complaints
arrival at route
Input
mistake/error
equipment
Dawn Ritchie, Matt Gratz, Angela Lewis, Mike Welch,
Bob Young
Measurement Technique
monitor # of customer calls thru
pmi, pcharts and bar charts
vcr report
dissatisfaction staffing
survey employee satisfaction
good pickup
Driver-trainer checklist; test new
drivers
training
Sample Size
all miss calls
20 trucks
Date (Orig):
4/7/02
Date (Rev):
4/12/02
Sample
Frequency
weekly
2x/day
Control
Method
PMI by
Customer
Service Mgr;
Pcharts and
bar charts
by SW Mgr
City
Supervisor
will visually
inspect vcr
forms
Survey by
Ops Mgr.
25 employees
4x/year
all new hires
90-day probation Audits by
peiod
trainer
Reaction Plan
Re-evaulate training
methods and hiring
practices
Send truck to garage for
repair; write driver up for
not filling out reports;
eventual termination
more training; more
communication; correct
the problem
more training;
termination
Attribute Sigma Calculator
ATTRIBUTE SIGMA CALCULATOR
Characteristic Under Study:
# of Units
Opportunity For Defects / Unit
Defects
DPU
DPMO
SIGMA (With Shift)
Garbage Misses
3,330,028
1
4,085
0.001226716
1226.716412
4.53
Sigma Shift
DPO
1.5
0.001227
Potential Savings
•
•
•
•
94 misses per Week
4,888 misses/yr
50% Reduction
2,444 misses/yr
Total Serv-all Savings
$195,520/yr
5 Yr Contract Total Savings
$977,600
NP Chart f or Total mi by phase
Sample Count
200
1
2
3
1
1
1
4
5
1
1
1
1
1 1
100
1
1
UCL=66.95
11 1
1
1 11 1
1
1 1
NP=46.5
1
LCL=26.05
1
1
0
0
10
20
30
Sample Number
40
50
I and MR Chart f or Total misses by phase
1
1
1
Individual Value
200
2
3
4
5
1
5
100
UCL=94.17
6
6 55 2
5
Mean=46.5
0
Subgroup
LCL=-1.168
0
10
1
20
2
30
3
40
4
50
5
Moving Range
100
1
UCL=58.56
50
R=17.92
0
LCL=0
Total misses
200
100
0
1
2
3
phase
4
5
Test f or Equal Variances f or Total misses
95% Confidence Intervals for Sigmas
Factor Levels
1
Bartlett's Test
Test Statistic: 17.992
2
P-Value
: 0.001
3
Levene's Test
4
Test Statistic: 1.608
P-Value
5
0
10
20
30
40
50
60
70
80
90
100
: 0.188
Initial
Initial Capability
Process Capability Analysis for init cap
USL
Process Data
USL
64.0000
Target
*
LSL
*
Mean
93.5556
Sample N
StDev (Within)
18
18.6692
StDev (Overall)
44.5757
Within
Overall
Potential (Within) Capability
Cp
CPU
*
-0.53
CPL
Cpk
*
-0.53
Cpm
*
Overall Capability
Pp
0
50
Observed Performance
100
150
200
Exp. "Within" Performance
250
Exp. "Overall" Performance
*
PPM < LSL
*
PPM < LSL
*
PPM < LSL
*
PPU
-0.22
PPM > USL
666666.67
PPM > USL
943303.06
PPM > USL
746348.01
PPL
*
PPM Total
666666.67
PPM Total
943303.06
PPM Total
746348.01
Ppk
-0.22
Final Capability
Process Capability Analysis for cap
USL
Process Data
USL
64.0000
Target
*
LSL
*
Mean
53.6538
Sample N
StDev (Within)
26
16.4539
StDev (Overall)
18.3082
Within
Overall
Potential (Within) Capability
Cp
CPU
*
0.21
CPL
Cpk
*
0.21
Cpm
*
Overall Capability
Pp
0
20
40
Observed Performance
60
80
100
Exp. "Within" Performance
120
Exp. "Overall" Performance
*
PPM < LSL
*
PPM < LSL
*
PPM < LSL
*
PPU
0.19
PPM > USL
307692.31
PPM > USL
264741.17
PPM > USL
285999.54
PPL
*
PPM Total
307692.31
PPM Total
264741.17
PPM Total
285999.54
Ppk
0.19
Project Tracking-Garbage
Project
Description
Process
Map
C&E
Matrix
Preliminary
FMEA
MSA
Owner
Sign-Off
Final Project
Report
Measure
Initial
Capability Study
Multi-Vari
Analyze
DOE (or other improvement)
Improve
Control
Plan
Control
Hand Off
Training
Final
Capability
Study
Statistical Tools Used
•
•
•
•
•
•
•
•
•
•
Control Charts: I-MR, N, P, C Charts
Chi Square
Proportions Tests
Pareto Charts
Moods Median
Test for Equal Variances
One-Way Anova
Dotplots
Boxplots
Histograms
Achievements
•
•
•
•
•
•
•
•
Reduced missed trash pickups by 50% over 12 months
NSA will save $195,000/yr or $977,000/5-yr contract
Improved City and National Serv-all partnership
Improved City and National Serv-all communication
Improved customer service
City of Fort Wayne Partnership manual
Routes visually inspected daily
NSA hired a trainer
Achievements
•
•
•
•
•
•
•
•
•
NSA improved training program
NSA updated driver-trainer checklist
Implemented a 90-day probation period for new hires
Drivers tested during training
NSA improved screening process for applicants
Reduced worker turnover
Hired additional workers
Offer driver relief pool
Hired helpers with CDL/Aid helpers to get CDL
Achievements
•
•
•
•
•
•
Better preventative maintenance
Reduced route size
Teamwork policy
Less fatigued workers
Supervisor manual developed
Provided collectors with appropriate tools More
communication between management and workers
• Improved workplace environment
• Increased appreciation shown
Achievements
•
•
•
•
•
Performance Measure Index (PMI)
Assistant City Supervisor
Audits
Added frequent misses to route sheets
Improved efficiency and organization of Dispatch
Office
• Offered incentives for drivers to have less than 15
misses/team/wk
• Duplicated route sheets for splitter routes
• Increased citizen satisfied
Accomplishments
• Trainer Hired
• Reduced Employee Turnover
• Reduced Fatigued Workers
• Implemented Teamwork Policy
• Management Changes
• Improved Communication
What’s Next?
• Continue to monitor weekly garbage misses
• Meet with the NSA supervisor to resolve any
unexpected problems
• Maintain a weekly goal of 1 miss per 1,000
households
Current Status (2006)
Average Number of Misses Per Week with 79,000
Households Serviced
187
154 149
137
150
100
116
108
102 89
80
80
50
M
ar
Ap
r
M
ay
Ju
ne
Ju
ly
Au
g
Se
pt
O
ct
No
v
De
c
0
Ja
n
Fe
b
# of Misses
200
Month
2006
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