IENG 471 Lecture 17: Introduction to Order Profiling
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Transcript IENG 471 Lecture 17: Introduction to Order Profiling
IENG 471 - Lecture 17
Introduction to Order Profiling
Major portion courtesy of
Dale T. Masel, Ohio University and the
2009 Material Handling Teacher’s Institute
7/21/2015
IENG 471 Facilities Planning
1
Order Profile
Definition: Order Profiling
A summary of the important characteristics
of the orders that a warehouse needs to fill
Examples of important characteristics
Demand for items What’s popular?
Quantities ordered What’s the workload?
Unit loads What equipment is needed?
Importance of Order Profiling
Provides information about our population,
which is what we usually need when we
design anything
We don’t design cars for individual drivers
We don’t design clothes for individual wearers
We don’t design warehouses for individual orders
Profile gives us insight on the
characteristics of the individuals that
comprise the population
Order Profiling as Art & Science
Art
Determining which
characteristics are
relevant for a
particular situation
Turning the
characteristics of the
order population into
an order fulfillment
system
Requires expertise in
warehouse design
Science
Converting available
data into data
required for a profile
Summarizing the
order population from
the available data
Focus of this
presentation
Where to Start: Data Requirements
SKUs
What’s being stored, and possibly how it is
being contained
Inventory
How much is being stored
Orders
What’s being processed, and
How much is being processed
Why bother profiling?
Trying to sort through data can be
overwhelming
Profiles are ways to organize the data
Don’t want to just rely on averages
Demand would exceed capacity 50% of the time
Value of profiling is that it provides a
quantitative description of what a distribution
center needs to be designed to handle
Example of a Typical Order
Order#8
# of Lines
SKU #
Qty
6
1481
15
1979
12
2777
6
3927
9
3979
7
2840
9
A month’s worth of orders...
Order#1
# of Lines
Order#2
Order#3
Order#4
SKU #
Qty
# of Lines SKU #
Qty
# of Lines SKU #
Qty
# of Lines SKU #
Qty
Order#28
Order#6
3
1481
6
2
1481
3
2
1481
11
2
1481
18
# of Lines SKU #
Qty
Order#5 1979
Order#8 2777
# of3979
Lines SKU6#
Qty
24
2840
4
15
Order#7
1481
16
# of Lines SKU #
Qty 3
#
of
Lines
SKU
#
Qty
1Order#30
2840
3
1524
18
Order#27
#
of
Lines
SKU
#
Qty
18
6
1481
12 Order#9 1979
6
1481
15
# of Lines SKU #
Qty3
#6of Lines SKU #
Qty
2777
#
of
Lines
SKU
#
Qty
1956
12
1979
12
1979
12
Order#26
Order#10
5
1901
13
3
4060
12
2705
27
1
2705
9
2777
6
# of Lines SKU1955
#
Qty 6
# of Lines 1481
SKU #
Qty
14
5422
24
Order#13
2840
6
1972
3927
9
3
3927
18 12
Order#12
1
2839
1524
7 9# of Lines SKU #
Qty
6079
12
1901
Order#115422
12 6
3979
7
# of Lines SKU #
Qty1972
2
2840
24
7
Order#17
Order#25
1524
# of Lines6717
SKU # 24 6Qty
2840
9
5
1524
13 1955
1481
6
15
#
of
Lines
#
Qty
#
of
Lines
SKU
#
Qty
SKU
5
1481
8
2840
34
Order#31
4
1979
11
2840
18
3
3122
15
3927
12
Order#16
Order#19
# of Lines SKU3906
#
Qty18
3906
13
5422
6
1481
3
#3of Lines SKU #
Qty
#
of
Lines
SKU
#
Qty
2
2839
3079
15
1481
15
6079
12
6079
18
Order#15
1
1979
12
4
1901
12
1481
6
5422
18 Order#20
2840
14
4817
24
# of Lines SKU #
Qty
1481
6
# of Lines SKU #
Qty
6717
12
Order#29 13
Order#2324
4
1972
4800
Order#21
2
2705
18
Order#18
# of Lines 18
SKU #
Qty
# of Lines6 SKU #
Qty
Order#22
1524
5100
# of2840
Lines SKU12#
Qty
# of Lines 4 SKU # 1981Qty
24
3
1901
24
#
Qty
1481
9
4
1972
6# of Lines SKU
Order#24
4
1979 1955 9
12
5340
12
Order#32
1
1481
12
1956
36
1524
10
# of Lines SKU #
Qty
6079 1481 18
12
# of Lines SKU #1481 Qty 18
1481
9
2
3122
18
1481 1524 17
6
2
3906
17
1979
18
2811
18
5100
13
1481
9
Profiling gives us a way to make sense out of all this data
Examples of Order Profiles
Item Family Profile
Order quantity
Unit Load
Lines per order
Cube per order
Item Family Profile
Want to find families of SKUs
Family = group of SKUs that can completely
fill a large number of orders
Items in a family are stored together
and not spread over facility
Reduces travel for pickers to get all items
for the order
Orders by Item Family
Order#15
Order#21
Order#29
Order#1
Order#5
Order#22
Order#28
Order#30
Order#6
Order#7
Order#9
Order#20
Order#24
Order#27
# of
# Lines
of
# Lines
of
#SKU
Lines
of
Lines
#SKU
of
Qty
Lines
#SKU
#SKU
Qty
#SKU
Qty
Qty
# Qty
# Lines
of
#SKU
of
Lines
#SKU
of
Qty
Lines
#SKU
# QtyQty
of#Lines
#Qty
Qty
# of#Lines
of
#SKU
Lines
of
# SKU
Lines
of
# Lines
SKU
SKU
#SKU
# Qty
# QtyQty
3 6 4 4 4 1481
3 1972
61981
131481
61901
24 12 16 13
121481
1 1481
5 1972
1979
1524
1524
241955
101481
12 18 14
1979
12 181979
1524
1481
1481
181481
91524
12 12 7
1955
6 91956
1956
1979
1524
6
1972
12 36 181972
7
1901
6
1955
15
1524
6
1
Family – A
0000-2500
5
14811524 8
28402840 18
39063927 18
30791481 15
54226079 18
13
34
12
3
18
Family-A & B & C
4060
5422
6079
Family – C
2501-4000
4001-7000
3122
39279 15 18
2839
5422
5422 6 12
6079
6717 12 24
Family-B & C
Order#18
Order#19
Order#23
Order#14
# Lines
of
# Lines
of
# Lines
ofSKU
Lines
SKU
#SKU
# Qty
# QtyQty
# of
#SKU
Qty
5 4 4 3
3
Family – B
# Lines
of
# Lines
of Lines
SKU
# Qty
# QtyQty
# of
SKU
#SKU
# of#Lines
of Lines
SKUSKU
# #Qty Qty
5
6 9 18 18
2 27772705
3122
1 2 2840
32705
2705 2840
27
2811 12 18
2840
6
Order#25
Order#10
Order#26
1 3 3
Order#11
Order#12
3
# of Lines SKU #
1979
1901
1901
1972
18 9 12 24
6079
1481
5340
1481
12 18 6 12
1481
4800
1481
6079
12 17 24 18
5100
510024 13 6
4817
6717
12
Family-A & C
Qty
12
24
12
Order#2
Order#3
Order#4
Order#8
Order#13
Order#16
Order#17
Order#31
Order#32
# SKU
of
Lines
# SKU
# of#Lines
of#Lines
ofSKU
#Lines
ofSKU
#Lines
of
#Qty
Lines
#Qty
ofSKU
#Qty
Lines
of#SKU
Qty
Lines
Qty
# Qty
#Qty Qty
#SKU
of
Lines
SKU
#SKU
Qty
2
2
2
43 21481
1979
11 3 17
21481
1122840
181979
2839
24 12
3906
61481
1 1481
15
3906
13 6 9
397928402777
6 1979
4 1481
15 12
1481
6 1481
1481
15
2777
6
2840
14
3927
9
3979
7
2840
9
Family-A & B
Plotting Item Family Percentages
30
Percent of Orders
25
20
15
10
5
0
A
B
C
AB
SKU Families
AC
BC
ABC
Information from the Profile
We get a lot of orders for only family A items and
only family B items
Items from family C are usually ordered with items
from family A or family B—rarely alone
Use this information to group items by family in
separate areas
Maximize number of orders that can be filled from a single area
Minimize the size of each area (to keep travel distance small)
If room for three aisles, where would you put aisles for A, B, C?
Order Quantity Profile
Look at what unit loads are needed to fill an order
Pallets
Cases
Eaches
A mix of these (progressive dimension system)
Store in quantities to make appropriate unit loads
available for picking
Easier for picker to handle
Efficient to pick
Improve picking accuracy
Plotting Order Quantity Percentages
45
40
Percent of Orders
35
30
25
20
15
10
5
0
Full
Broken
Case Quantity
Mixed
Information from the Profile
Most orders are filled with full cases, so most of
the inventory will be stored as cases stacked on a
pallet
Storage equipment will be some kind of pallet rack
For less than pallet quantities, different storage
equipment is possible, depending on conditions
Pick from an open carton stacked on pallet with rest of full
cartons
Store individual cartons on separate shelving or bins
Unit Load Profiling
Look at what unit loads (full or partial)
customers order
The unit loads that SKUs are shipped
in should be the unit loads you store
Avoids wasted time repacking the SKUs
For SKU 1481
the most-ordered
SKU in this example
Unit Load
Order#12
Order#2
Order#32
Order#15
Order#21
of Lines
# of# Lines
SKUSKU
# #QtyQty
ofSKU
Lines
# of#Lines
of #Lines
SKU
# SKU
#Qty #Qty Qty
of Lines
# of#Lines
SKUSKU
# #Qty Qty
5 2
4
6
1481 13 3
1524
3979 34 6
2840
3927
12
1481
3
6079
18
3 units ordered
(½ case)
Order#1
Order#13
Order#19
Order#31
# of#Lines
ofSKU
#Lines
SKU
#Qty#Qty Qty
of#Lines
#Lines
ofSKU
#QtySKU
3
2
4
6 2839
2148128401901
24 12 3
197914811481
24 1481
6 6 6
24
1524 4800
18
5100
6
6 units ordered
(1 case)
4
2
Order#8
Order#17
197219723906
13 6 17
152415241481
18 10 9
14811481 9 9
19561979 36 18
9 units ordered
(1½case)
ofSKU
SKU
#Qty#Qty Qty
# of#Lines
of#Lines
#Lines
ofSKU
#Lines
#QtySKU
1
4
5148114811981
12 1972
12 24
1979 1955
12 1481 12
1955 1481
6 6079 12
1972 1524
12 4817 6
1901
6 6717
1524
6
12 units ordered
(2 case)
14811979 15
19793906 12
27771481 6
39272840 9
3979
7
2840
9
11
13
15
14
15 units ordered
(2½ case)
Order#5
Order#22
Order#29
Order#14
6
4
18
12
12
24
12
Order#4
Order#23
of Lines
# of#Lines
SKUSKU
# #Qty Qty
2
3
14811901 18 24
27775340 15 12
1481
18
18 units ordered
(3 case)
Plotting Unit Load Percentages
For a single SKU
20
15
10
5
Portion of Case Ordered
3
2 5/6
2 2/3
2 1/2
2 1/3
2 1/6
2
1 5/6
1 2/3
1 1/2
1 1/3
1 1/6
1
5/6
2/3
0
1/2
Percent of Orders
25
Information from the Profile
50% of orders for this SKU require only fullcarton quantities
6, 12, 18 items
More than 75% of orders require a mix of
only full-carton and half-carton quantities
3, 6, 9, 12, 15, 18 items
Packaging the items in bundles of 3 within the main
carton would reduce picking time for orders
needing 3, 9 , or 15 items
1 move to get 3 items
Lines per Order Profile
Each SKU on an order represents a “line”
No. Lines = No. Locations a picker must visit
May need to pick multiple units of each line
item
No. Lines ≠ No. Units ordered by a customer
Lines per Order
Order#13
Order#20
Order#24
Order#32
Order#3
Order#31
Order#2
Order#4
Order#16
Order#22
Order#9
Order#6
Order#10
# of#Lines
of#Lines
ofSKU
#Lines
ofSKU
#Lines
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
SKU
#QtySKU
#Qty#Qty Qty
# of#Lines
of#Lines
ofSKU
#Lines
ofSKU
#Lines
ofSKU
#Qty
Lines
SKU
#QtySKU
#Qty#Qty Qty
1
1
1
11979
114812705
12 2840
12 2839
9 3
2
9
2
2
22840
22705
23122
2423906
1821481
18 2839
17 1481
11 1481
3 3 18
148128402811
6 1481
12 2840
18 1481
9 3979
4 2777
6 6 15
Order#19
Order#29
Order#17
Order#15
Order#18
Order#21
Order#1
Order#23
Order#26
Order#27
Order#7
Order#25
Order#28
#SKU
of SKU
# of#Lines
of#Lines
ofSKU
#Lines
ofSKU
#Lines
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
#Qty
#Qty
#Qty#
Qty Qty
SKU
# of#Lines
of#Lines
ofSKU
#Lines
ofSKU
#Lines
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
SKU
#QtySKU
#Qty#Qty Qty
3
4
3
Lines
3
31901
33927
6 4060
24 2777
18 3122
12 6 15
31481
3
1481
16
197953405422
24 5422
12 2705
12 5422
24 27 6
1979
18
152414816717
18 6079
18 2840
24 6079
12 6 12
1956
12
# of#Lines
of#Lines
of
#SKU
Lines
of SKU
Lines
# SKU
#Qty
SKU
#Qty
# QtyQty
5
5 5 197219011481
181524
13
148114812840
122840
14
607915243906
123927
7
481719723079
241481
7
671719555422
126079
15
4
41901
41981
41979
12 1972
24 1979
11 1972
13 9
148119553906
6 1524
12 6079
13 1524
18 18
480014811481
24 1481
12 1481
15 1481
9 17
510015242840
6 1956
6 5100
14 1979
36 13
Order#5
Order#8
Order#14
Order#30
Order#11
Order#12
5
4
8 13
18 34
18 12
15 3
18 18
# of#Lines
of Lines
SKUSKU
# #Qty Qty
6
6
14811481 12
19791979 12
19552777 6
19723927 12
19013979 6
15242840 6
15
12
6
9
7
9
6
10
9
18
Plotting Lines per Order
Percentages
30
Percent of Orders
25
20
15
10
5
0
1
2
3
4
Lines per Order
5
6
Information from the Profile
Provides insight on amount of travel involved
collecting all of the items for an order
Provides insight on equipment / method for
carrying items picked by pickers
Profile also indicates percentage of items that
consist of just 1 line
These orders could be packed as they are picked,
since items from other zones aren’t needed
May have a dedicated area for packing these
orders since they don’t need sortation
(most appropriate when 1 unit of a line is ordered)
Cube per Order Profiling
Cube is used to describe the space in
a warehouse
All three dimensions are used for storage,
so we’re concerned about volume, not area
Can be…
Amount of space occupied by a unit load
Amount of space available for storage in the
racks/shelves
assuming
0.1 ft3/unit
for all SKUs
Cube per Order
Order#16
Order#22
Order#9
Order#6
Order#10
Order#2
Order#3
Order#31
Order#4
Order#13
Order#20
Order#24
Order#32
Order#1
Order#27
Order#28
Order#25
Order#7
Order#19
Order#21
#Qty
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
ofSKU
Lines
SKU
#QtySKU
#Qty#Qty Qty
# of#Lines
of#Lines
ofSKU
#Lines
ofSKU
#Lines
ofSKU
Lines
#Qty
1
1
1
22705
3 11 3
11979
11481
1222840
1222839
9 1481
3 1481
9 2839
397928401481
6 4 6
0.1 to 2.5 ft3
#Qty
ofSKU
#Qty
Lines
ofSKU
Lines
SKU
#Qty#Qty Qty
# of#Lines
of
# Lines
of
# SKU
Lines
of#Lines
SKU
of
##SKU
Lines
of
#SKU
Qty
#Lines
#ofSKU
Qty
#Lines
Qty
ofSKU
#Qty
Lines
ofSKU
#Qty
Lines
ofSKU
Lines
#Qty
#QtySKU
2
2 2 2 1481
2 2840
3 2705
3122
324
3906
18
31481
1834060
1741481
6 43122
12 2777
16 1901
15 1972
6 12
318
24 5422
24 2705
18 1481
6 1524
27 6
27771481
2840
15
28111481
6 121979
18 5422
9 1979
152460791956
18 6079
12 2840
12 4800
12 1481
6 24
51001979 6
6
10
9
18
2.6 to 5.0 ft3
Order#29
Order#23
Order#26
Order#17
Order#18
Order#30
Order#5
Order#8
Order#15
Order#11
Order#12
Order#14
of
Lines
Qty
# of#Lines
of#Lines
of
#SKU
Lines
of##SKU
Lines
#
SKU
#Qty
#Qty
#Lines
Qty
QtySKU
of#
Lines
ofSKU
#Lines
ofSKU
SKU
SKU
##
#
Qty#Qty Qty
# of#Lines
#Lines
of#Lines
ofSKU
#Lines
ofSKU
SKU
#QtySKU
#Qty#Qty Qty
3
3
4
24
4 4 1901
111481
9 1481
24
181981
5 3927
6 1979
61979
1901
13 12
12
131979
18 1979
534054223906
126079
121955
1481
14 12
12
151955
17 2777
148167171481
181481
241481
1524
7 6
6
2840
51001524
14
13
197219723927
7 12
195519013979
15 6
15242840 6
5.1 to 7.5 ft3
15
12
6
9
7
9
4
5
5
13 1972
5197214811524
8 13
152428402840
18 1481
18 34
148139063927
9 6079
18 12
195630791481
36 4817
15 3
542260796717
18 18
≥ 7.6 ft3
18
12
12
24
12
Plotting Cube per Order
Percentages
40
Percent of Orders
35
30
25
20
15
10
5
0
0-2.5
2.6-5
5.1-7.5
Cube per Order
>7.5
Information from the Profile
Cube of an order represents size of
shipment to the customer
Can affect method used to pack the order
Pallet vs. Carton
Size of carton
May also affect shipping method
Parcel delivery vs. Less-than-Truck Load (LTL)
Item Activity Profile
Item Activity reflects how frequently it’s ordered
and picked
Each order for an item represents additional work
for warehouse
Travel to storage
Retrieval from storage
Considering Item Activity when assigning a
storage location can reduce the amount of work
when the item is ordered
Especially for travel
Typical Item Activity
SKU #1481
Units
21,330/week
Pallets 150 units
Cube
0.6 ft3/carton
Activity of many SKUs…
SKU #3927
SKU #1524
SKU #6079
SKU #3906
SKU #1481
Units 1,2400/week Units 48/week
SKU #1979
SKU #3122
Units 48/week
Units 1,2400/week
Units
SKU #5422
Pallets 150 units
Pallets 90units
Units 1,2400/week
Unitsunits
1,2400/week
SKU #1956
Pallets 90units
Pallets 150
Pallets
Units
1,2400/week
0.6 ft3/cartonCube 1
ft3/carton
Pallets 150Units
unitsCube
150 units
48/week
Cube
1.2 ft3/carton SKU #2777
Cube Pallets
0.6 ft3/carton
Cube
Pallets 150 units
SKU #3079
SKU #6717
Cube 0.6 Pallets
ft3/carton
Cube 0.6 ft3/carton
90units
Units
1,2400/week
3
Cube 0.6 ft /carton
Units 1,2400/week SKU #2705 Units 1,2400/week
3/carton
Cube
1
ft
Pallets 150 units
SKU #2840
SKU #1972
Pallets 150 units
Pallets 150 units
Units 1,2400/week
Cube
0.6
ft3/carton
Units 1,2400/week
3
Units 1,2400/week
Cube 1.2 ft /cartonPallets 150 units
Cube#3979
0.6 ft3/carton
SKU
Pallets 150 units
Pallets 90 units
SKU #4817
Cube
0.6 ft3/carton
Units 1,2400/week
SKU #5100
3
Cube 0.6 ft /carton
Cube 1 ft3/carton
Units 1,2400/week
Pallets 150 units
Units 19/week
SKU #1981
SKU #5340
SKU #2839
Pallets 150 units
Cube 1ft3/carton
Pallets 45 units
Units 1,2400/week
3/carton
Units 12/week
Units 12/week
Cube
0.6
ft
3
Cube#1901
1.2 ft /carton
SKU
Pallets 150 units
SKU #2811
Pallets 45units
Pallets 150 units
Units
SKU #4800
SKU1,2400/week
#1955
Cube 0.6 ft3/carton
3/carton
Units 18/week
#4060
CubeSKU
1.2ft
Cube 1.2 ft3/carton
Pallets
units
Units 1,2400/week
Units1501,2400/week
Pallets 45 units
Units 1,2400/week
Pallets 150 units
Cube
0.6 ft3/carton
Pallets 90 units
Cube 1ft3/carton
Cube
0.645
ft3units
/carton
Pallets
Cube 1.2 ft3/carton
Cube 1.2 ft3/carton
Creating the Item Profile
Rank SKUs from most units/week to least
Usually divided into three classes (A, B, C)
A – Fastest movers
Probably 5% – 10% of SKUs
Consider keeping these in a special “Forward Pick Area”
B – Average
Probably 10% - 15% of SKUs
Consider keeping these near front end of aisles
C – Slowest movers
Probably 80% or more of SKUs
Store these in longer travel locations
Demand Profile
SKU #1481
SKU #1901
SKU #2705
SKU #3906
SKU #6079
SKU #1524
SKU #5422
SKU #1956
Units #1979
SKU
Units Units Units Units Units Units Units 48/week
Pallets
Units #2840
SKU
Pallets Pallets Pallets Pallets Pallets Pallets Pallets 90units
Cube
Pallets
Units 1,2400/week
Cube Cube Cube Cube Cube Cube Cube
Cube 150 units
Pallets
Cube
0.6 ft3/carton
SKU #1972
SKU #3122
SKU #4817
SKU #3979
Units #3927
Units #2777
Units #5100
Units #2839
SKU
SKU
SKU
SKU
Pallets
Pallets
Pallets
Pallets
Units
Units
Units
Units
SKU #6717
SKU #1981
SKU #2811
SKU #4060
Cube
Cube
Cube
Cube
Pallets
Pallets
Pallets
Pallets
Units
Units
Units
Units
SKU #1955
SKU #4800
SKU #3079
SKU #5340
Cube
Pallets Cube
Pallets Cube
Pallets
Pallets 12/week
Units
Units
Units Cube
Units
Cube
Pallets Cube
Pallets Cube
Pallets Cube
Pallets 45units
Cube
Cube Cube Cube 1.2 ft3/carton
1 ft3/carton
Plotting the Demand Profile
100
90
C
Percent of Cartons Shipped
80
B
70
60
50
40
A
30
20
10
0
SKU # ( Ranked from Maximum Demand to Minimum Demand)
Information from the Profile
Most popular SKUs represent most of
demand, but a small portion of total SKUs
Pareto’s Law: 20% of the SKUs account for 80%
of the items ordered
We need to do a good job storing and picking these SKUs
because they represent most of the work
A large percentage of SKUs (maybe even
more than half) represent the smallest
category of demand
Applications of the Item Profile
Grouping SKUs into classes for storage
Identifying assignments in Forward and
Reserve storage areas
Storage and material handling strategies
Getting Started
Profiling requires data
Need several months, to provide a picture of the long-term
situation (seasonality)
Data will probably require preparation
Identify which data fields in the Work Management System
(WMS) contain the needed data
May have data values that need to be fixed
Design shouldn’t start until you have a profile that
describes your warehouse situation
Data Preparation
Data may not be complete
Empty fields where data wasn’t available or recorded
Data may not be accurate
Invalid SKUs
Negative inventory levels
Need to clean up this information
Fix values where possible
Delete entries if fix isn’t possible
Probably will need to be done manually
What comes next…
Completed profiles give data that is
needed for an effective facility design
Amount of space (cube) for storage
Types of storage equipment
Profiles are also used to design
operations
Methods for order picking
Equipment for order picking
In Summary
Order profiling…
… needs to be done before a warehouse is
designed (or redesigned)
… is never complete because the order
characteristics change and the warehouse design
and management need to be updated to reflect
these changes
… if done accurately, yields excellent results and
useful information
… if done incorrectly, can produce inaccurate
conclusions and lead to bad decisions
Sources for further reading
Warehouse and Distribution Science, John
Bartholdi and Steven Hackman (2008).
Available on-line at
http://www2.isye.gatech.edu/~jjb/wh/
Facilities Planning, James Tompkins, John White,
Yavuz Bozer, and Jose Tanchoco, 3rd Edition
(2002) Wiley.
World-Class Warehousing and Material Handling,
Edward Frazelle (2001) McGraw-Hill.
Questions & Issues?
7/21/2015
IENG 471 Facilities Planning
42