Facilities Planning and Design

INE 425
Lec 6

1
 CHAPTER 4
FLOW, SPACE, AND ACTIVITY
RELATIONSHIPS
 Direct clustering algorithm (DCA)
Example: Using the DCA method to determine
alternative groupings of machines (bottleneck
machines) for the following figure
Direct clustering algorithm (DCA)

Ord e red ma ch in e -p a rt matrix

Direct clustering algorithm (DCA)

Formation of cells with “bottleneck” machine 2 or 3-

 Direct clustering algorithm (DCA)

Formation of cells with duplicate of (a) machine 2 and (b) machine 3.

 Layout Types Based on Material Flow
System
The type of material flow system is determined by the
makeup of the activities or planning departments
among which materials flow. As noted previously, there
are four types of production planning departments:
1. Production line departments
2. Fixed materials location departments
3- Product family departments
4. Process departments
Product Layout
Advantages and Limitations of Product
Layout
 Product Layout
• Advantages
1. Since the layout corresponds to the sequence of operations,
smooth and logical flow lines result.
2. Since the work from a process is fed directly into the next one,
small in-process inventories result.
3. Total production time per unit is short.
4. Since the machines are located so as to minimize distances
between consecutive operations, material handling is reduced.
5. Little skill is usually required by operators at the production line;
hence, training is simple, short, and inexpensive.
6. Simple production planning control systems are possible.
7. Less space is occupied by work in transit and for temporary
storage.
 Product Layout
Limitations
1. A breakdown of one machine may lead to a complete
stoppage of the line that follows that machine.
2. Since the layout is determined by the product, a change in
product design may require major alternations in the layout.
3. The “pace” of production is determined by the slowest
machine.
4. Supervision is general, rather than specialized.
5. Comparatively high investment is required, as identical
machines (a few not fully utilized) are sometimes distributed
along the line.
Fixed Product Layout
Advantages and Limitations of Fixed
Product Layout
 Fixed Product Layout
• Advantages
1. Material movement is reduced.
2. Promotes job enlargement by allowing individuals or
teams to perform the “whole job”.
3. Continuity of operations and responsibility results
from team.
4. Highly flexible; can accommodate changes in product
design, product mix, and product volume.
5. Independence of production centers allowing
scheduling to achieve minimum total production
time
 Fixed Product Layout
• Limitations
1. Increased movement of personnel and equipment.
2. Equipment duplication may occur.
3. Higher skill requirements for personnel.
4. General supervision required.
5. Cumbersome and costly positioning of material and
machinery.
6. Low equipment utilization
Group Layout
Advantages and Limitations of Group
Layout
 Group Layout
• Advantages
1. Increased machine utilization.
2. Team attitude and job enlargement tend to occur.
3. Compromise between product layout and process
layout, with associated advantages.
4. Supports the use of general purpose equipment.
5. Shorter travel distances and smoother flow lines
than for process layout.
 Group Layout
• Limitations
1. General supervision required.
2. Higher skill levels required of employees than for
product layout.
3. Compromise between product layout and process
layout, with associated limitations.
4. Depends on balanced material flow through the cell;
otherwise, buffers and work-in-process storage are
required.
5. Lower machine utilization than for process layout.
Process Layout
Advantages and Limitations of Process
Layout
 Process Layout
• Advantages
1. Better utilization of machines can result;
consequently, fewer machines are required.
2. A high degree of flexibility exists relative to
equipment or man power allocation for specific
tasks.
3. Comparatively low investment in machines is
required.
4. The diversity of tasks offers a more interesting and
satisfying occupation for the operator.
5. Specialized supervision is possible.
 Process Layout
• Limitations
1. Since longer flow lines usually exist, material handling is
more expensive.
2. Production planning and control systems are more
involved.
3. Total production time is usually longer.
4. Comparatively large amounts of in-process inventory result.
5. Space and capital are tied up by work in process.
6. Because of the diversity of the jobs in specialized
departments, higher grades of skill are required.
 Activity relationships
• Measuring the activities among departments is one of
the most important elements in the layout of
departments within a facility.
• To evaluate alternative arrangements, activity
relationships must be established.
• Activity relationships may be specified in a quantitative
or qualitative manner.
• Quantitative measures may include pieces per hour,
moves per day, or pounds per week.
• Qualitative measures may range from an absolute
necessity that two departments be close to each other
to a preference that two departments not be close to
each other.
 Activity relationships
• In facilities having large volumes of materials,
information, and people moving between departments,
a quantitative measure of flow will typically be the basis
for the arrangement of departments.
• On the contrary, in facilities having very little actual
movement of materials, information, and people
flowing between departments, but having significant
communication and organizational interrelations, a
qualitative measure of flow will typically serve as the
basis for the arrangement of departments.
• Most often, a facility will have a need for both
quantitative and qualitative measures of flow, and both
measures should be used.
 From-to chart
• From-To Chart measures the flows between departments
• It resembles mileage charts

Mileage chart Triangular mileage chart.

 From-to chart procedure
1- List all departments down the row and across the column
following the overall flow pattern.
2- Establish a measure of flow for the facility that accurately
indicates equivalent flow volumes.
– If the items moved are equivalent (size, weight, value, risk
of damage, shape), the measure could be the number of
the trips
– If the items moved vary in size, weight, value, risk of
damage, shape, and so on, then some common unit of
measure may be established so that the quantities
recorded in the from-to chart represent the proper
relationships among the volumes of movement.
3- Record the flow volumes in the From-To Chart based on the
flow paths for the items to be moved and the established
measure of flow
 Quantitative Flow Measurement
• Flows may be measured quantitatively in terms of the
amount moved between departments. The chart most
often used to record these flows is a from-to chart. As
shown in the following Figure
 From-To Chart -simple
Possible alternative layouts

S-shaped flow
straight-line flow

U-shaped flow;
W-shaped flow
 Example
• A firm produces three components. Components 1 and 2 have the
same size and weight and are equivalent with respect to
movement. Component 3 is almost twice as large and moving two
units of either component 1 or 2 is equivalent to moving 1 unit of
component 3. The departments included in the facility are A, B, C,
D, and E. the overall flow path is A-B-C-D-E. The quantities to be
produced and the component routings are as follows:
 Solution
Apply the From-to chart procedure

In the above from-to chart, the circled numbers represent component numbers and
the number of following the circled numbers indicate the volume of equivalent flows
for the component.
 Qualitative Flow Measurement
• Flows may be measured qualitatively using the
closeness relationship values developed by Muther
and given in the following Table

closeness relationships values

 Qualitative Flow Measurement
Relationship Chart may include the closeness values in conjunction with
reasons for the value
 Qualitative Flow Measurement
• A Relationship (REL) Chart is constructed as follows
1. List all departments on the relationship chart.
2. Conduct interviews of surveys with persons from each
department listed on the relationship chart and with the
management responsible for all departments.
3. Define the criteria for assigning closeness relationships and
itemize and record the criteria as the reasons for relationship
values on the relationship chart.
4. Establish the relationship value and the reason for the value for
all pairs of departments.
5. Allow everyone having input to the development of the
relationship chart to have an opportunity to evaluate and discuss
changes in the chart.
 Space Requirements
• Perhaps the most difficult determination in facilities
planning is the amount of space required in the facility.
The design year for a facility is typically 5 to 10 years in
the future.
• Considerable uncertainty generally exists concerning
the impact of technology, changing product mix,
changing demand levels, and organizational designs for
the future. The facilities planner then has the difficult
task of projecting true space requirements for the
uncertain future.
 Space Requirements
• In determining space requirements for storage
warehousing activities, inventory levels, storage units,
storage methods and strategies, equipment
requirements, building constraints, and personnel
requirements must be considered.
• In manufacturing and office environments, space
requirements should be determined first for individual
workstations; next, departmental requirements should
be determined based on the collection of workstation
in the department.
 Workstation Specification
• Workstations are places where specific operations
are performed. Productivity of a firm is definitely
related to the productivity of the workstation.
• A workstation includes space for equipment,
materials, and personnel.
• The equipment space for a workstation consists of
space for:
1. The equipment
2. Machine travel
3. Machine maintenance
4. Plant services.
 Workstation Specification
• Equipment space requirements should be readily available from
machinery data sheets(provided by the supplier).
• If this data is not available, the following information must be
obtained for each machine:
1. Machine manufacturer and type
2. Machine model and serial number
3. Location of machine safety stops
4. Floor loading requirement
5. Static height at maximum point
6. Maximum vertical travel
7. Static width at maximum point
8. Maximum travel to the left
9. Maximum travel to the right
10. Static depth at maximum point
11. Maximum travel toward the operator
12. Maximum travel away from the operator
13. Maintenance requirements and areas
14. Plant service requirements and areas
 Workstation Specification
• Floor area requirements for each machine, including machine
travel, can be determined by multiplying total width (static
width plus maximum travel to the left and right) by total
depth (static depth plus maximum travel toward and away
from the operator). To the floor area requirement of the
machine add the maintenance and plant service area
requirements. The resulting sum represents the total
machinery area for a machine.
• The materials areas for a workstation consist of space for:
1. Receiving and storing materials
2. Holding in-process materials
3. Storing and shipping materials
4. Storing and shipping waste and scrap
5. Tools- fixtures, jigs, dies, and maintenance materials.
 Department Specification
• Once the space requirements for individual workstations have been
determined, the space requirements for each department can be
established. To do this, we need to establish the departmental
service requirements.

• Departmental area requirements are not simply the sum of the

areas of the individual workstations included with the department.
It is quite possible tools, dies, equipment maintenance, plant
services, housekeeping items, storage areas, operators, spare parts
kanban boards, information-communication-recognition boards,
problem boards, and andons may be shared to save space and
resources

• Additional space is required within each department for material

handling within the department. Aisle space requirements can be
approximated, since relative sizes of the loads to be handled are
known
 Department Specification

Workstation sketch required to determine total area requirements

 Department Specification

Aisle Allowance Estimates

 Example
• 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 ft for turret
lathes, 4 × 14 ft for screw machines, and 5 × 6 ft for
chuckers. Personnel space footprints of 4 × 5 ft are
used. Materials storage requirements are estimated to
be 20 ft2 per turret lathe, 40 ft2 per screw machine,
and 50 ft2 per chucker.
• A aisle space allowance 13% is used.
Solution
• The space calculations are summarized in the following table

total of 1447 ft2 of floor space is required for the planning department
 Visual Management and Space
Requirements
• Aisles should be located in a facility to promote effective
flow. Aisles may be classified as departmental aisles and
main aisles.
• Planning aisles that are too narrow may result in congested
facilities having high levels of damage and safety problems.
Conversely, planning aisles that are too wide may result in
wasted space and poor housekeeping practices
• Aisles widths should be determined by considering the type
and volume of flow to be handled by the aisle. The type of
flow may be specified by considering the people and
equipment types using the aisle.
Visual Management and Space
Requirements

Recommended Aisle Widths for Various Types o f Flow

Thank you