Facility Design-Week 4
Flow, Space, and Activity Relationship
and Personnel Requirement
Anastasia L.M.
1
Space Requirements & Space Availability

Determination of the Production Rate

Determination of Batch Production Quantities

Economic Order Quantity Models

Reject Allowance Problem

Determination of Equipment Requirements

Determination of Employee Requirements

Manual Assembly Operators

Machine Operators

Determination of Space Requirements

Tables for Aisle Allowance, Food Services and Restrooms

Other Methods to Determine Space Requirements

Parking Space
2
Determination of the Production Rate


The production rate of a department is
a major determinant of the amount of
space required. The production rate of a
processing station is the number of units
produced per time unit. The production
rate can be determined from a marketing
forecast of the finished product.
Notation:
a = arrival rate of raw material.
d = demand rate of a product.
p = production rate of a processing station.
s = scrap probability of an inspection
station.
r = rework probability of an inspection
station.
a
1
p
r
1
s
d
3
3
1
Example 1
p3
p1
4
2
Consider the operation process chart shown in the
Figure. The percentage of rejected parts at
inspection stations 1, 2 and 3 are 5%, 4% and
6%, respectively. The annual operating time is
2,500 hours, and the annual demand forecast for
the product is 490,000 units. Due to possible
forecasting errors, 10,000 additional units per
year are required. Find the production rate at
each station.
p4
p2
s1
2
1
s2
(1)
(2)
5
p5
6
p6
3
s3
d
4
Example 1 Solution
d 
1
p1
s1
(good units)
(1  s 3 )

200
0 .94
4
p4
p2
 200 units / hr .
2 ,500
d
p3
2
490 ,000  10 ,000
p5  p6 
3
 212 .76 units / hr .
1
2
(2)
s2
(1)
5
p3  p4 
p5
(1  s 2 )

212 .76
0 .96
p5
 221.63 units / hr .
6
p1  p 2 
2  p5
(1  s 1 )

2  212 .76
0 .95
p6
 447 .92 units / hr .
3
d
s3
5
Example 2
Consider a product that requires a single operation. After the
operation is performed, each unit is inspected. A unit passes
inspection with probability 0.92, is scrapped with probability 0.05, or
has to be reworked with probability 0.03. If the demand for this
product is 82,000 units per year and the annual operating time is
2,500 hours, determine the production rate at the processing station.
d 
a
1
p 
p
r
1
82 ,000
2 ,500
d
(1  s  r )
 32 .80 units / hr . (good units)

32 .80
0.92
 35.65 units / hr .
s
a  p  (1  r )  35.65  0.97  34 .58 units / hr .
d
6
Determination of Batch Production Quantities

In process layout, a given machine can be used to process
different products. In certain product layouts, the same
production (or assembly) line can be used to produce (or
assemble) similar products with the same process plan. In
both of these cases, jobs are produced in batches. Optimal
batch production quantities can be computed using an
inventory control model.

Process layouts are also used in job shops where “oneshot” jobs are received and processed. Rather than
producing for inventory, the order is processed and shipped
to the customer. The reject allowance problem determines
the optimal production lot size for a given order when a
portion of the lot may be defective.
7
Economic Order Quantity (EOQ) Model

Assumptions:




Items are withdrawn from stock continuously at a constant demand rate a
(units/time unit).
Items are produced or ordered Q units at a time, and all Q units arrive
instantaneously, i.e., there is no lead time.
This is a continuous review process, i.e., we look at the inventory continuously
and when it reaches zero, we order.
Notation:
K = setup cost ($/order).
c = unit purchasing or production cost ($/unit).
h = unit holding cost ($/unit/time unit).
X(t) = inventory on hand at time t.
T = cycle time (time between consecutive orders).
8
Reject Allowance Problem
In job shops, one time jobs are received and processed. There is no
production to inventory. Each batch is only produced once. If there is a
defective rate, how many units must be produced? The following
expected profit model is formulated to determine the optimal batch size:
Q
m ax Q E [ P ( Q )]   {R ( Q , x )  C ( Q , x )} p Q ( x )
x0
where
Q = lot size,
x = number of good parts,
pQ(x) = P{X=x : lot size is Q}, x=0,1,…,Q,
R(Q,x) = revenue for producing Q parts with exactly x good ones,
C(Q,x) = cost for producing Q parts with exactly x good ones,
P(Q,x) = R(Q,x) - C(Q,x) : profit for producing Q parts with x good ones,
E[] = expected value.
9
Example 2

A company receives an order for 10 machined parts. The unit sale price is
$1,000. Only one production can be made due to the long setup time
required and short due date of the order. If 8 or fewer parts are
acceptable, the customer will cancel the order. If 9 or 10 parts are
acceptable, the customer will purchase all of them. If more than 10 parts
are acceptable, the customer will only buy 10. The remaining parts, good
or bad, can be sold for $25 each. The cost of producing a part is
estimated to be $600. Find the optimal lot size.

Probability mass function pQ(x):
L ot size
10
11
12
13
14
7
0.2
8
0.3
0.2
0.1
9
0.3
0.3
0.2
0.2
N um ber of good parts
10
11
0.2
0.3
0.2
0.3
0.2
0.2
0.3
0.2
0.2
12
13
14
0.2
0.2
0.3
0.1
0.2
0.1
10
Example 2 Solution

25  Q

R ( Q , x )   1000 x  25 ( Q  x )

1000  10  25 ( Q  10 )
x  0 , ... ,8
x  9 ,10
x  11, ... , Q
C(Q,x) = C(Q) = 600Q
Q
Q
E [ P ( Q )]   { R ( Q , x )  C ( Q , x )} p Q ( x )   [ R ( Q , x )  p Q ( x )]  C ( Q )
x0
x0
8
10
x0
x9
Q
E [ P ( Q )]   25  Q  p Q ( x )   [1000  x  25 ( Q  x )] p Q ( x ) 
10
Q
x9
x  11
 (10000  25 ( Q  10 )] p Q ( x )  600  Q
x  11
  975  x  p Q ( x )  9750  p Q ( x )  575  Q
11
Example 2 Solution (cont.)





E[P(10)]
E[P(11)]
E[P(12)]
1680.00
E[P(13)]
2080.00
E[P(14)]
1700.00

= 975(90.3+100.2) + 97500 - 57510 = -1167.50
= 975(90.3+100.3) + 97500.2 - 57511 = 1182.50
= 975(90.2+100.3) + 9750(0.2+0.2) - 57512 =
= 975(90.2+100.2) + 9750(0.3+0.2+0.1) - 57513 =
= 975(100.2) + 9750(0.2+0.3+0.2+0.1) - 57514 =
Optimal lot size:
Expected profit:
Q* = 13 units
E[P(Q*)] = $2,080.00
12
Determination of Equipment Requirements
Given the desired production rate at each processing stage,
we can determine the number of required machines:
 n P ij  Tij 

Mj  
 i  1 H ij 
wherePij = production rate for product i on machine j (units/period),
Tij = processing time for product i on machine j (hrs./unit),
Hij = time units available per period for the processing of
product i on machine j (hrs.),
Mj = number of machines of type j required,
n = number of products.
13
Example 3
CIN-A1 Workcenters are used to produce three types of parts, {1, 2,
3}. Production rates and unit processing times for the different items
are given in the following table:
Item type
i
1
2
3
P roduction rate
P i (units/day)
100
200
50
U nit processing tim e
T i (m in./unit)
6
9
12
The facility operates one shift per day (8 hrs./day = 480 min./day).
Determine the number of workcenters required to meet production
requirements.
Hi = min. available to process item i per day (Hi = 480 min.),
MA = number of workcenters.
 3 P i  Ti   100  6  200  9  50  12 
MA   
  
   6 .25   7 w orkcenters C IN  A 1.
H
480


i 
i  1
14
Employee Requirements - Manual Assembly
In the case of manual assembly operations, the number of employees
required is determined in the same way machine requirements are
calculated:
 n P ij  Tij 

Aj  
 i  1 H ij 
where
Pij = production rate for assembly operation j of product i
(units/period),
Tij = standard time for assembly operation j of product i (hrs./unit),
Hij = time units available per period for assembly operation j of
product i (hrs.),
Aj = number of operators required for assembly operation j,
n = number of products.
15
Multiple Activity Chart Analysis of Multi-Machine Assignment
O-1 M-1
O-1 M-1 M-2
O-1 M-1 M-2 M-3
L-1
L-1
L-1
0
2
L
I
L
R
I&T
U-2
6
R
U-2
U
U
L-2
L
L
I&T
I&T
10
R
U-3
U
L-3
12
U-1
U
U-1
U
R
L
O : Operator
M : Machine
L : Load
U : Unload
I : Inspection
T : Travel
R : Automatic run
: Idle time
I&T
R
14
L-1
20
LEGEND:
I&T
R
L-2
8
18
R
R
4
16
L
L
L-1
L
U-1
U
L-1
L
I&T
U-2
R
R
I
I&T
R
R
U-2
U
U
16
Employee Requirements - Machine Operators

The number of machine operators required depends on the number of
machines tended by one or more operators. The determination of the
number of machines to be assigned to one operator can take two
approaches:
 deterministic,
 probabilistic.

A deterministic approach is to employ the multiple activity chart. This
chart shows the multiple activity relationships graphically against a time
scale. The chart is useful in analyzing multiple activity relationships,
specially, when non-identical machines are supervised by a single
operator.

Let
a = concurrent activity time (loading, unloading, etc.),
b = independent operator activity time (inspecting, packing, etc.),
t = independent machine activity time (automatic run),
n’ = maximum number of machines that can be assigned to an
operator.
17
Employee Req. - Machine Operators (cont.)
n' 
at
ab

Note that n’ may be non-integer.

Let
m = (integer) number of machines assigned to an operator,
Tc = repeating cycle time,
I0 = idle operator time during a repeating cycle,
Im = idle time per machine during a repeating cycle.
 at
Tc  
m (a  b)
m  n'
(1)
m  n'
(a  t )  m (a  b )
I0  
0

m  n'
m  n'
18
Employee Req. - Machine Operators (cont.)
m (a  b)  (a  t)
Im  
0


Let
m  n'
c1 = cost per operator - hr.,
c2 = cost per machine - hr.,
TC(m) = cost per unit produced, based on the assignment of m
machines per operator.
TC ( m )  (c1  m  c 2 )

m  n'
Tc
(2)
m
Substituting (1) into (2),
 ( c 1  m  c 2 )( a  t )

TC(m)  
m
 ( c 1  m  c 2 )( a  b )
m  n'
m  n'
19
Employee Req. - Machine Operators (cont.)

We want to find the value of m that minimizes TC(m).

Note that
and

If n’ is integer, n’ is the optimal number of machines per operator.
Otherwise, let n < n’ < n+1. In this case, TC(n) and TC(n+1) have to be compared:
for m  n’,
for m > n’,
 
where

TC(n)
T C ( n  1)

m ()
m ()
 TC(m) (),
 TC(m) ().
( c 1  n  c 2 )( a  t )
[ c 1  ( n  1) c 2 ] n ( a  b )

n

n'
 n1 n
c
  1c .
2
If  <1, assign n machines per operator.
If  >1, assign n+1 machines per operator.
20
Example 4
Semiautomatic machines are used to produce a particular product. It
takes 4 minutes to load and 3 minutes to unload a machine. A machine
runs automatically for 25 minutes in producing one unit of the product.
Travel time between machines is 20 seconds. While machines are
automatically running, the operator inspects the unit previously produced;
75 seconds are required to inspect one unit. An operator costs $15 per
hour, and a machine costs $40 per hour.
a) Determine the number of machines assigned to an operator to minimize
the cost per unit produced.
a = 4 + 3 = 7 min., b = 20 + 75 = 95 sec. = 1.58 min., t = 25 min.,
c1 = $15/hr. = $0.25/min., c2 = $40/hr. = $0.67/min.

n' 
7  25
7  1.58
T C ( 3) 
 3.73
( 0 .25  3  0 .67 )( 7  25 )
3
 $24.0
 m* = 3 machines/operator.
T C ( 4 )  ( 0 .25  4  0.67 )( 7  1.58 )  $25.03
21
Example 4 (cont.)
b) For what range of values of machine cost per hour will the optimal
assignment determined in part (a) be economic.
TC(3)  TC(4),
( 0 .25  3  c 2 )( 7  25 )
3
 ( 0 .25  4  c 2 )( 7  1.58 ),
(0.25 + 3c2) 1.24  (0.25 + 4c2),
0.0607  0.27c2 
c2  0.225,
c2  $0.225/min. = $13.48/hr.
22
Space Req’s.: Workstation Specification


A workstation consists of the fixed assets
needed to perform a specific operation(s).
The equipment space consists of space for
- The equipment
- Machine travel
- Machine maintenance
- Plant services
23
Space Req’s.: Workstation Specification

A Equipment space requirements are available from machinery data
sheets (provided by the supplier). If this data is not available, the
following information must be obtained for each machine:
- Machine manufacturer and type
- Maximum travel to the left
- Machine model and serial number
- Maximum travel to the right
- Location of machine safety stops
- Static depth at maximum point
- Floor loading requirement
operator
- Maximum travel towards the
- Static height at maximum point
operator
- Maximum travel away from the
- Maximum vertical travel
areas
- Maintenance requirements and
- Static width at maximum point
requirements and areas
- Plant service
24
Space Req’s.: Workstation Specification (cont.)

Area requirements for a machine:
Total width = (static width) + (max. travel to left) +
(max. travel to right)
Total depth = (static depth) + (max. travel toward
operator) + (max. travel away from operator)
Area (machine + machine travel) = (total width) * (total
depth)
25
Space Req’s.: Workstation Specification (cont.)

The materials areas consists of space for






Receiving and storing materials
In-process materials
Storing and shipping materials
Storing and shipping waste and scrap
Tools, fixtures, jigs, dies, and maintenance materials
The personnel areas consists of space for



The operator
Material handling
Operator ingress and egress
26
General Guidelines for Design of Workstations

The operator should be able to pick up and discharge materials
without walking or making long or awkward reaches.

The operator should be utilized efficiently and effectively.

The time spent manually handling materials should be minimized.

The safety, comfort and productivity of the operator must be
maximized.

Hazards, fatigue and eye strain must be minimized.

A workstation sketch is required to determine total area
requirements.
27
Space Req’s.: Department Specification

Department area requirements are not simply the sum of the
areas of the individual workstations included in each department.

Machine maintenance, plant services, incoming and outgoing
materials, and operator ingress and egress areas for various
workstations must be combined.

Additional space is required for material handling within the
department. Space requirements for aisles can be approximated
since the relative sizes of the loads to be handled are known.
28
Tables for Aisle Allowance
Table 1. Aisle Allowance Estimates
If th e L arg est L o ad is
2
L ess th an 6 ft
2
B etw een 6 an d 1 2 ft
2
B etw een 1 2 an d 1 8 ft
2
G reater th an 1 8 ft
A isle A llo w an ce
(P ercen tag e o f N et
A rea R eq u ired )
5 – 10
10 – 20
20 – 30
30 - 40
In Example 5,
10 
86
12  6
 (20  10)  13.33 % .
Table 2. Recommended Aisle Widths
for Various Types of Flow
T y p e o f F lo w
A isle W id th
(ft)
T racto rs
3 -to n F o rk lift
2 -to n F o rk lift
1 -to n F o rk lift
N arro w A isle T ru ck
M an u al P latfo rm T ru ck
P erso n n el
P erso n n el w ith D o o rs O p en in g
in to th e A isle fro m O n e S id e
P erso n n el w ith D o o rs O p en in g
in to th e A isle fro m T w o S id es
12
11
10
9
6
5
3
6
8
29
Example 5
A planning department for the ABC Company consists of 13 machines that perform turning
operations. Five turret lathes, six automatic screw machines, and two chuckers are
included in the planning department. Bar stock, in 8-ft bundles, is delivered to the
machines. The footprints for the machines are 412 ft2 for the turret lathes, 414 ft2 for
the screw machines, and 56 ft2 for the chuckers. Personnel space footprints of 45 ft2 are
used. Materials storage requirements are estimatefd to be 20 ft2 per turret lathe, 40 ft2
per screw machine, and 50 ft2 per chucker. An aisle space allowance of 13% is used. The
space calculations are summarized in the table below.
2
S ervice R equirem ents
W orkstation
Q uantity
P ow er
C om pressed
A ir
O ther
A rea (ft )
F loor
L oading
C eiling
H eight
E quipm ent
M aterial
P ersonnel
T otal
T urret
L athe
5
440 V
AC
10 C F M @
100 psi
150 P S F
4’
240
100
100
440
S crew
M achine
6
440 V
AC
10 C F M @
100 psi
190 P S F
4’
336
240
120
696
C hucker
2
440 V
AC
10 C F M @
100 psi
150 P S F
5’
60
100
40
200
N et A rea R equired
13% A isle A llow ance
T otal A rea R equired
1336
174
1510
30
Service and Manufacturing Facilities
Organization
Showers
Lavatories
Water Closets
Water
Fountain
Others
Restaurants
-
1 per 200
1 per 75
1 per 500
1service
sink
Arenas (capacity
more than 3000)
-
1 per 200 1 per 120 (male); 1 1 per 1000 1 service
(male); 1 per 60 (female)
sink
per
150
(female)
Churches
-
1 per 200
1 per 150 (male); 1 1 per 1000 1 service
per 75 (female)
sink
Schools
-
1 per 50
1 per 50
1 per 100
Airports
-
1 per 750
1 per 500
1 per 1000 1 service
sink
Factories
Section
411
1 per 100
1 per 100
1 per 1000 1 service
sink
Hospitals
1 per 15
1 per room 1 per room
1 per 100
1 service
sink
Prisons
1 per 15
1 per cell
1 per 100
1 service
sink
Hotels
1
per 1 per room 1 per room
room
-
1 service
sink
Dormitories
1 per 8
1 per 100
1 service
sink
1 per 10
1 per cell
1 per 10
1 service
sink
31
Service and Manufacturing Facilities
Organization
Parking spaces
Restaurants (with drivethrough facilities)
One space per 75 square feet of floor area or 1.5 persons
(whichever is greater)
Theaters, Arenas, and
Assembly areas
One space per 8 feet of bench length or 4 seats (whichever is
greater)
Secondary schools and
Colleges
One space per 8 students, one-and-a-half spaces per classroom,
and number of spaces for gymnasium/assembly hall seating
Factories
One space per 1000 square feet of area plus number of spaces for
offices
Hospitals
Two spaces per bed
Churches
One space per three persons
Hotels
One space per guest room plus number of spaces for accessory
uses
Warehouses
One space per 2000 square feet of floor area
32
Food Services
Table 3. Shift Timing for 30 min.
Lunch Breaks
B eg in n in g o f
L u n ch B reak
1 1 :3 0
1 1 :5 0
1 2 :1 0
1 2 :3 0
T im e S at D o w n
In C h air
End of
L u n ch B reak
1 1 :4 0 am
1 2 :0 0 no o n
1 2 :2 0 p m
1 2 :4 0 p m
1 2 :0 0 no o n
1 2 :2 0 p m
1 2 :4 0 p m
1 :0 0 p m
am
am
pm
pm
Table 4. Space Requirements
for Cafeterias
C lassificatio n
A llo w an ce p er
2
P erso n (ft. )
C o m m ercial
In d u strial
B an q u et
16 – 18
12 – 15
10 – 11
Table 5. Space Requirements
for Full Kitchens
N u m b er o f
M eals S erv ed
1 0 0 – 2 00
2 0 0 – 4 00
4 0 0 – 8 00
8 0 0 – 1 30 0
1 3 0 0 – 20 0 0
2 0 0 0 – 30 0 0
3 0 0 0 - 5 0 00
A rea
R eq u irem en ts
2
(ft. )
5 0 0 – 1 00 0
8 0 0 – 1 60 0
1 4 0 0 – 28 0 0
2 4 0 0 – 39 0 0
3 2 5 0 – 50 0 0
4 0 0 0 – 60 0 0
5 5 0 0 – 92 5 0
33
Example 6
 Statement:
If a facility employs 600 people and they are to
eat in three equal 30 min. shifts, how much
space should be planned for the cafeteria with
vending machines, serving lines, or a full
kitchen?
34
Example 6 (cont’)

Solution:

If 36-in. square tables are to be utilized, Table 4 indicates 12
ft.2 are required for each of the 200 employees to eat per
shift. Therefore, a 2,400 ft.2 cafeteria should be planned. If a
vending area is to be used in conjunction with the cafeteria,
an area of 200 ft.2 should be allocated for vending machines.
Thus, a vending machine food service facility would require
2,600 ft.2

A service line may serve 70 employees in the first third of the
meal shift. Therefore, three serving lines of 300 ft.2 each
should be planned. A total of 3,300 ft.2 would be required for
a food service facility using serving lines.

A full kitchen will require 3,300 ft.2 for serving lines plus (from
Table 5) 2,100 ft.2 for the kitchen. Therefore, a total of 5,400
ft.2 would be required for a full kitchen food service facility.
35
Restrooms
Table 6. Number of Toilets Needed
for Number of Employees
M ax im u m N u m b er o f
E m p lo y ees P resen t
at an y O n e T im e
M in im u m N u m b er
o f T o ilets N eed ed
1 – 15
16 – 35
36 – 55
56 – 80
81 – 110
1 1 1 – 1 50
O v er 1 5 0
1
2
3
4
5
6
1 ad d itio n al to ilet
fo r each ad d itio n al
4 0 em p lo y ees
Table 7. Number of Sinks Needed for Type
of Employment and Number of Employees
Type of
E m p lo y m en t
N o n -in d u strial
(O ffice an d
P u b lic F acilities)
N u m b er o f
E m p lo y ees
M in im u m N u m b er
O f S in k s
1 – 15
16 – 35
36 – 60
61 – 90
91 – 125
O v er 1 2 5
1
2
3
4
5
1 sin k fo r each
ad d itio n al 4 5
em p lo y ees
1 sin k fo r each
1 0 em p lo y ees
1 – 100
In d u strial
(M an u factu rin g
an d w areh o u se
F acilities)
O v er 1 0 0
1 sin k fo r each
ad d itio n al 1 5
em p lo y ees
36
Other Methods to Determine Space Req’
1. Production Center Method/ Kalkulasi

Perhitungan kebutuhan ruang lebih akurat.

Dimulai dgn membreak down aktivitas atau area,
kemudian menentukan jumlah area untuk setiap
luasan/space dan mengalikan dengan jumlah
element/mesin yg dibuat & menambahkan extra space.

Production center terdiri dari suatu mesin tunggal
ditambah dgn associated equipment, &space required
untuk operasinya.

Work space, additional maintenance space & storage
space juga ditambahkan kedalam kebutuhan ruang untuk
mesin. Metode ini biasanya digunakan untuk menghitung
manufacturing area.
37
Other Methods to Determine Space Req’
2. Converting Method
 The
present space requirements are converted to those
required for the proposed layout. It is important to
establish valid assumptions, because the total space
required is not a linear function of the production
quantity.

This method is used to determine space requirements for
supporting service, storage areas, etc.
38
Other Methods to Determine Space Req’
3. Space-Standards Method
 In certain cases industry standards can be
used to determine space requirements.

Standards may be established based on past
successful applications.
4.Roughed-out Layout Method
 Templates or models are placed on the layout
to estimate the general configuration and
space requirements.
39
Other Methods to Determine Space Req’
5. Ratio Trend and Projection Method
One can establish a ratio of square feet to some other
factor that can be measured and predicted for the proposed
layout. For example,
square
square
square
square
feet
feet
feet
feet
per
per
per
per
machine
operator
unit produced
labor-hour
40
Other Room that Should be Included in Space
Determination
1.
storage
10. Supervision
2.
In-process inventory
storage
11. QC dan inspection
12. Health & Medical Facilities
3.
Warehouse
4.
Aisle
5.
Receiving and Shipping
14. Lavatories, wash rooms,
etc
6.
Material Handling
Equipment Storage
15. Offices
13. Food Service
16. Employee & visitor parking
7.
Toolrooms & Tool cribs
8.
Maintenance
17. Receiving & shipping
parking
9.
Packaging
18. Other storage.
41
Parking Space
( angular  one-way )
( cross aisle )
( cross aisle )
( 900  two-way )
42
43
Parking Space (cont.)
Table 8. Parking Dimensions for a 7.5-ft. Compact Automobile Parking
Space Width and a 8.5-ft. Standard-Sized Automobile Parking Space
Width
A ngle
(degrees)
A utom obile
P arking
S pace W idth
P arallel to the
A isle (ft.)
45
45
60
60
75
75
90
90
C om pact
S tandard
C om pact
S tandard
C om pact
S tandard
C om pact
S tandard
10.5
12.0
8.7
9.8
7.8
8.8
7.5
8.5
P arking
S pace D epth
P erpendicular
to the A isle (ft.)
17.0
17.5
17.7
19.0
17.3
19.5
16.0
18.5
A isle
W idth (ft.)
C ross
A isles
O ne-w ay
(ft.)
C ross
A isles
T w o-w ay
(ft.)
P arking
S pace +
½ A isle
2
S pace (ft. )
11.0
13.0
14.0
18.0
17.4
25.0
20.0
28.0
12.0
14.0
12.0
14.0
12.0
14.0
12.0
14.0
22.0
24.0
22.0
24.0
22.0
24.0
22.0
24.0
236
288
215
274
203
282
195
276
44
Table 4.5 Minimum dimensions for parking stalls
Parking Angle
Aisle-width
(two-way)
Aisle-width
(one-way)
Stall width
Stall length
76-90o
25 feet
15 feet
9 feet
20 feet
30-75o
25 feet
12 feet
9 feet
22 feet
0-29o
18 feet
12 feet
9 feet
25 feet
45
Parking Space (cont.)
Parking space
Depth perpendicular to aisle (19.0 ft.)
Width parallel to
aisle (9.8 ft.)
1/2 aisle space
allocated
Parking space
Aisle width (18.0 ft.)
Parking space + 1/2 aisle space (for 600 standard)
= 19.0  9.8 + 18.0  9.8 / 2 = 186.2 + 88.2  274
ft.2
46
Example 7
Problem Statement:
A new facility is to have 200 employees. A
survey of similar facilities indicates that one
parking space must be provided for every two
employees and that 35% of all automobiles
driven to work are compact automobiles. The
available parking lot space is 180 ft. wide and
200 ft deep. What is the best parking layout?
47
Example 7

Solution:
If the new facility were to have the same number of parking
spaces as similar facilities, 100 spaces would be required. Of
these 100 spaces, 35 could be for compact automobiles.
However, not all drivers of compact cars will park in a
compact space. Therefore, only 25 compact spaces will be
provided. A parking layout consisting of one-way traffic
between five rows of 900 standard-sized automobiles and one
row of 900 compact automobiles would require a parking lot
width of
5 (18.5) + 3 (28) + 1 (16) = 192.5 ft.
Similarly, four rows of 900 standard-sized automobiles, one
row of 750 standard-sized automobiles, and one row of 750
compact automobiles would require a parking lot width of
4 (18.5) + 2 (28) + 1 (19.5) + 1 (17.3) + 1 (25) =
191.8 ft.
which is too wide to be placed in a lot 180 ft. wide.
48
Example 7 (cont.)
Replacing the 750 aisle with a 600 aisle still requires 184.7 ft.
Four rows of 900 standard-sized automobiles, one row of 450
standard-sized automobiles, and one row of 450 compact
automobiles requires a parking lot width of
4 (18.5) + 2 (28.0) + 1 (17.5) + 1 (17.0) + 1
(13.0) = 177.5 ft.
This configuration will be utilized.
Leaving 24 ft. for two-way cross-aisle traffic at the front of
the lot and 14 ft. for one-way cross-aisle traffic at the rear of
the lot, the 900 standard-sized automobile rows can each
accommodate
49
Example 7 (cont.)
 200  ( 24  14 ) 
 19 autom obiles


8 .5


The last 900 standard-sized row does not require the 14
ft. one-way cross-aisle. Therefore, it accommodates
 200  24 
 20 autom obiles


8 .5


The 450 standard-sized row can accommodate
 200  ( 24  14 ) 
 13 autom obiles


12 .0


50
Example 7 (cont.)
The 450 compact automobile row is the first and
does not require the 14.0 ft. one-way cross-aisle. It
can accommodate
 200  24 
 10 .5   16 autom obiles


51
Example 7 (cont.)
Hence, a total of
3 (19) + 20 + 13 + 16 = 106 automobiles
can be accommodated, with 15% being allocated to
compact automobiles. The following Figure illustrates the
plan for the parking lot.
If the compact automobile row is replaced by standardsized automobiles, the lot still fits within the 180 ft.  200
ft. configuration and 104 cars may be accommodated.
Therefore, a decision must be made regarding the
advantages of providing compact automobile spaces versus
not segmenting the parking lot.
52
Parking Lot for Example
20 Standard-sized automobiles (900)
19 Standard-sized automobiles (900)
19 Standard-sized automobiles (900)
19 Standard-sized automobiles (900)
13 Standard-sized automobiles (450)
16 Compact automobiles (450)
53
OSHA, ADA and Local Codes
54
OSHA, ADA and Local Codes
55
OSHA
ADA
and
Local
Codes
56
57
58
59
Table 4.3 Accessible spaces for persons with disability
Total spaces in
parking lot
1-25
26-50
51-75
76-100
101150
151200
201300
301400
401500
5011000
Minimum
Accessible
spaces
1
2
3
4
5
6
7
8
9
2%
60
61
62
Aesthetics
63
Aesthetics
64
Aesthetics
65
Aesthetics
66
Aesthetics
67
Aesthetics
68
Aesthetics
69
Aesthetics
70
Aesthetics
71
Cubicles layout
72
Cubicles layout
73
Iowa State DOT layout
74