Facility Planning
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•
•
•
Definition and Objectives
Engineering Design Process
Important Factors to Evaluate Facility Plans
Evaluation of Alternative Facility Plans
- Pairwise Comparison Technique
- Factor Analysis Technique
- Prioritization Matrix
•
•
•
•
Material Handling Checklist
Principles of Material Handling
Objectives of Facility Layout
Traditional Facility Layout Procedures
- Naddler’s Ideal System Approach
- Apple’s Plant Layout Procedure
- Muther’s Systematic Layout Planning
- Immer’s Basic Steps
- Reed’s Plant Layout Procedure
• Information Gathering
- Information about Product
- Information about Schedule
- Information about Process
Definition of Facility Planning
Facility Planning determines how an activity’s tangible fixed assets
best support achieving the activity’s objectives.
Examples:
a. In manufacturing, the objective is to support production.
b. In an airport, the objective is to support the passenger airplane interface.
c. In a hospital, the objective is to provide medical care to patients.
Hierarchy of Facility Planning
Facility
Location
Structural
Design
Facility
Planning
Facility
Design
Layout
Design
Handling
System Design
Location:
is the placement of a facility with respect to customers, suppliers, and other
facilities with which it interfaces.
Structure:
consists of the building and services (e.g., gas, water, power, heat, light, air,
sewage).
Layout:
consists of all equipment, machinery, and furnishings within the structure.
Handling System: consists of the mechanism by which all interactions required by the layout
are satisfied (e.g., materials, personnel, information, and equipment
handling systems).
Significance of Facility Planning
1. Since 1955, approximately 8% of the gross national product (GNP) is
spent in new facilities in the U.S. :
Industry
GNP %
Manufacturing
Public Utilities
Commercial
Communication
•••
3.2
1.6
1.5
1.0
•••
Total
8.0
2. It is estimated that 20 to 50 % of operating costs within manufacturing
are attributed to material handling. It is generally agreed that effective
facilities planning can reduce material handling costs by 10 to 30 %.
Strategic Facilities Planning Issues
1.
2.
Number, location, and sizes of warehouses and/or distribution centers.
Centralized versus decentralized storage supplies, raw materials, work-in-process,
and finished goods for single- and multi-building sites, as well as single- and
multi-site companies.
3. Acquisition of existing facilities versus design of model factories and distribution
centers of the future.
4. Flexibility required because of market and technological uncertainties.
5. Interface between storage and manufacturing.
6. Level of vertical integration, including "subcontract versus manufacture"
decisions.
7. Control systems, including materials control and equipment control.
8. Movement of materials between buildings, between sites.
9. Changes in customers' and suppliers' technology as well as firm's own
manufacturing technology and materials handling, storage, and control technology.
10. Design-to-cost goals for facilities.
Facility Planning Objectives
1. Support the organization's mission through improved material
handling, materials control, and good housekeeping.
2. Effectively utilize people, equipment, space, and energy.
3. Minimize capital investment.
4. Be flexible and promote ease of maintenance.
5. Provide for employee safety and job satisfaction.
Engineering Design Process
• Typically, design problems do not have well-defined, unique, optimum
solutions. We are interested in obtaining a satisfactory solution.
• General Procedure for Solving Engineering Design Problems
1. Formulate the problem.
2. Analyze the problem.
3. Search for alternative solutions.
4. Evaluate the design alternatives.
5. Select the preferred design.
6. Implement the design.
Application of the Engineering Design
Process to Facility Planning
1. Define (or redefine) the objective of the facility:
Specify quantitatively the products to be produced or service to be provided.
2. Specify the primary and support activities to be performed in accomplishing the
objective:
Requirements for primary activities include operations, equipment, personnel, and
material flows.
3. Determine the interrelationships among all activities:
Both qualitative and quantitative relationships should be defined.
4. Determine the space requirements for all activities:
These are determined considering the equipment, materials, and personnel requirements.
5. Generate alternative facility plans:
Including alternative facility locations and alternative designs for the facility.
6. Evaluate alternative facility plans:
Determine the important factors (see list of factors). For each candidate plan, evaluate if
and how those factors will affect the facility and its operations.
Application of the Engineering Design
Process to Facility Planning (cont.)
7. Select a facility plan:
Cost may not be the only major consideration.
Use the information in step 6 to determine a plan (pairwise comparison is a good
ranking procedure).
8. Implement the facility plan:
Considerable amount of planning must precede the construction of a facility or the
layout of an area.
9. Maintain and adapt the facility plan:
The facility plan must be modified as new requirements are placed, e.g., new energy
saving measures, changes in product design may require different flow pattern or
handling equipment, etc.
10. Redefine the objective of the facility:
Similar to step 1.
Changes in product design and/or quantities may require changes into the layout plan.
Important Factors to Evaluate Facility Plans
In developing well-thought facilities design alternatives it is important to look into issues
such as:
a) Layout characteristics
- total distance traveled
- manufacturing floor visibility
- overall aesthetics of the layout
- ease of adding future business
b) Material handling requirements
- use for the current material handling equipment
- investment requirements on new equipment
- space and people requirements
Important Factors to Evaluate Facility Plans (cont.)
c) Unit load implied
- impact on WIP levels
- space requirements
- impact on material handling equipment
d) Storage strategies
- space and people requirements
- impact on material handling equipment
- human factors risks
e) Overall building impact
- estimated cost of the alternatives
- opportunities for new business
Pairwise Comparison Technique
It is a good ranking procedure. All combinations of two candidate plans are ranked for each
factor.
If n = number of candidate plans, and m = number of factors, the total number of
comparison is mn(n-1)/2.
It is a good procedure in testing for inconsistencies, e.g.,
A > B,
B > C, and
C > A.
If there are not inconsistencies and, for example, four candidate plans (A, B, C, and D), the
pairwise comparison may produce the following results:
A<B
B<C
A<C
B>D
C>D
A>D
Next, a factor analysis technique can be used to determine the facility plan, i.e., assign a
weight to each factor, and compute the total weight for each candidate plan.
Factor Analysis Technique
The facility plan scoring method is a very popular, subjective-decision making
tool that is relatively easy to use. It consists of these steps:
Step 1.
List all factors that are important - that have an impact on the facility
plan decision.
Step 2.
Assign an appropriate weight (typically between 0 and 1) to each
factor based on the relative importance of each.
Step 3.
Assign a score (typically between 0 and 100) to each facility plan
with respect to each factor identified in Step 1.
Step 4.
Compute the weighted score for each factor for each facility plan by
multiplying its weight by the corresponding score.
Step 5.
Compute the sum of the weighted scores for each facility plan and
choose a facility plan based on these scores.
Example 1
A payroll processing company has recently won several major contracts
in the Midwest region of the United States and Central Canada and wants
to open a new, large facility to serve these areas. Because customer
service is so important, the company wants to be as near its “customers”
as possible. A preliminary investigation has shown that Minneapolis,
Winnipeg, and Springfield, Illinois are the three most desirable locations,
and the payroll company has to select one of these. A subsequent
thorough investigation of each location with respect to eight important
factors generated the raw scores and weights. Using the location scoring
method, determine the best location for the new payroll processing
facility.
Example 1 (cont.)
Factors and weights for three locations
Score
Weight
Factor
Minneapolis
Winnipeg
Springfield
0.25
Proximity to customer
95
90
65
0.15
Land and construction prices
60
60
90
0.15
Wage rates
70
45
60
0.10
Property taxes
70
90
70
0.10
Business taxes
80
90
85
0.10
Commercial travel
80
65
75
0.08
Insurance costs
70
95
60
0.07
Office services
90
90
80
Example 1 Solution
Weighted scores for three locations
Weighted Score
Factor
Minneapolis
Winnipeg
Springfield
Proximity to customer
23.75
22.50
16.25
Land and construction prices
9.00
9.00
13.50
Wage rates
10.50
6.75
9.00
Property taxes
7.00
9.00
7.00
Business taxes
8.00
9.00
8.50
Commercial travel
8.00
6.50
7.50
Insurance costs
5.60
7.60
4.80
Office services
6.30
6.30
5.60
Sum of weighted scores
78.15
76.65
72.15
Prioritization Matrix
The prioritization matrix can be used to judge the relative importance of each criterion as
compared to each other. Table 1 represents the prioritization of the criteria for the facilities
design example. The criteria are labeled to help in building a table with weights:
A. Total distance traveled
G. Space requirements
B. Manufacturing floor visibility
H. People requirements
C. Overall aesthetics of the layout
I. Impact on WIP levels
D. Ease of adding future business
J. Human factor risks
E. Use of material handling equipment
K. Estimated cost of alternative
F. Investment in new material handling equipment
The weights typically used to compare the importance of each pair of criteria are:
1 = equally important
5 = significantly more important
1/5 = significantly less important
10 = extremely more important
1/10 = extremely less important
Prioritization Matrix (cont.)
Note that the values in cells (i, j) and (j, i) are reciprocals. The resulting relative importance
is presented in the last column in parenthesis. The most important criterion for facilities
design selection is the impact on WIP levels (weight = 18.3), followed by the estimated cost
of the solution (weight = 13.5).
This same methodology can be employed to compare all facilities design alternatives in each
weighted criterion. For example, suppose five layout alternatives are generated; namely, P,
Q,. R, S, and T. Table 2 represents the ranking of the layout alternatives based on the impact
of WIP levels criterion.
If we construct a similar table for the remaining ten criteria, we will be able to evaluate each
layout alternative in the eleven criteria to identify the best layout. The format of this final
table is presented in Table 3. The last column is computed as in Tables 1 and 2. The row
totals (represented by ) are added to obtain the grand total, after which the percentages
(%P, …, %T) are determined. These percentages tell us the relative goodness of each layout
alternative. These results should be presented to plant management to facilitate final
decisions regarding the layout.
Table 1: Prioritization Matrix for the
Evaluation of Facilities Design Alternatives
Criteria
A
B
C
D
E
F
G
H
I
J
K Row totals (%)
A
1
5
10
5
1
1
1
1
1
5
1
B
1/5 1
5
1/5 1/5 1/10 1/5 1/5 1/10 1/5 1/5
C
1/10 1/5 1
1/10 1/10 1/10 1/5 1/5 1/10 1/10 1/10 2.3 (0.7)
D
1/5 5
10
1
1/5 1/5 1/5 1/5 1/10 1/5 1/10 17.4 (5.4)
E
1
5
10
5
1
1
5
5
1/5
1
1/5
34.4 (10.7)
F
1
10
10
5
1
1
5
5
1
1
1
41.0 (12.7)
G
1
5
5
5
1/5 1/5 1
5
1/5
1/5 1/5
23.0 (7.1)
H
1
5
5
5
1/5 1/5 5
1
1/10 1/5 1/5
22.9 (7.1)
I
1
10
10
10
5
1
5
10
1
1
5
59.0 (18.3)
J
1/5 5
10
5
1
1
5
5
1
1
5
39.2 (12.2)
K
1
5
10
10
5
1
5
5
1/5
1/5 1
43.4 (13.5)
7.7
56.2 86.0 51.3 14.9 6.8
Column
Total
32.6 37.6 5.0
10.1 14.0
32.0 (9.9)
7.6 (2.4)
322.2
Table 2: Prioritization of Layout Alternatives
Based on WIP Levels
Layout
WIP
Levels
P
Q
R
S
P
1
5
10
1/10 1/5
Q
1/5 1
1/5 1/10 1/10
1.6 (2.2)
R
1
5
1
5
22.0 (30.0)
S
10
10
1/10 1
1/5
21.3 (29.0)
T
5
10
1/5 5
1
21.2 (28.9)
Column
Total
17.2 31.0 2.5
10
T
16.2 6.5
Row totals (%)
7.3 (9.9)
73.4
Table 3: Ranking of Layouts by All Criteria
Criteria
ABCDEFGH
I
J K Row totals (%)
P
.099  .183 = .018
 (%P)
Q
.022  .183 = .004
 (%Q)
R
.300  .183 = .055
 (%R)
S
.290  .183 = .053
 (%S)
T
.289  .183 = .053
 (%T)
Column
.183
Grand Total
Material Handling Checklist
– Is the material handling equipment more than 10 years old?
– Do you use a wide variety of makes and models which require a high spare parts
inventory?
– Are equipment breakdowns the result of poor preventive maintenance?
– Do the lift trucks go too far for servicing?
– Are there excessive employee accidents due to manual handling of materials?
– Are materials weighing more than 50 pounds handled manually?
– Are there many handling tasks that require 2 or more employees?
– Are skilled employees wasting time handling materials?
– Does material become congested at any point?
– Is production work delayed due to poorly scheduled delivery and removal of
materials?
– Is high storage space being wasted?
– Are high demurrage charges experienced?
Material Handling Checklist (cont.)
– Is material being damaged during handling?
– Do shop trucks operate empty more than 20% of the time?
– Does the plant have an excessive number of rehandling points?
– Is power equipment used on jobs that could be handled by gravity?
– Are too many pieces of equipment being used because their scope of activity is
continued?
– Are many handling operations unnecessary?
– Are single pieces being handled where unit loads could be used?
– Are floors and ramps dirty and in need of repair?
– Is handling equipment being overloaded?
– Is there unnecessary transfer of material from one container to another?
– Are inadequate storage areas hampering efficient scheduling of movement?
– Is it difficult to analyze the system because there is no detailed flow chart?
– Are indirect labor costs too high?
Questions to be Resolved in Developing a
Material Handling Plan
1. Should automated storage/retrieval systems (AR/RS), computer controlled
narrow aisle trucks, manually operated trucks, or some combination be used for
palletized storage/retrieval?
2. Should miniloads, automated carousels, manually operated carousels, operator
aboard storage/retrieval machines, or come combination be used for
storage/retrieval of small parts?
3. Should automated guided vehicles, tow lines, pallet conveyors, tractor-trailer
trains, pallet trucks, or some combination be used to deliver loads to/from
palletized storage?
4. Should fixed path, variable paths, or some combination be used for material
handling to/from/within manufacturing?
5. Should centralized or distributed storage of work-in-process be used? How
should it be stored, moved, protected, and controlled?
Questions to be Resolved in Developing a
Material Handling Plan (cont.)
6. Should transporter-conveyors, light duty roller conveyors, or carts be used to
transport kits and parts to/from assembly stations? Should kitting be performed
at all? If so, what issue quantities should be used?
7. Should modular workstations, modular handling systems, and/or modular storage
units be used in manufacturing and assembly?
8. Should real-time inventory control be used to shop floor control and storage of
raw material/work-in-process/finished goods? What data entry technology is
appropriate?
9. Should block stacking, deep-lane storage, mobile rack, double-deep rack, drivein/drive-through rack, selective rack, or some combination be used for pallet
storage?
10. Should automatic loading/unloading of trailers be planned for receiving and
shipping? If so, when, where, and for what materials?
Top 10 Principles of Material Handling
Principle 1. Planning Principle
All material handling should be the result of a deliberate plan where the needs,
performance objectives and functional specification of the proposed methods are
completely defined at the outset. The plan should be developed in consultation
between the planner(s) and all who will use and benefit from the equipment to be
employed.
Principle 2. Standardization Principle
Material handling methods, equipment, controls and software should be standardized within the limits of achieving overall performance objectives and without
sacrificing needed flexibility, modularity, and throughput. Standardization means
less variety and customization in the methods and equipment employed.
Principle 3. Work Principle
Material handling work should be minimized without sacrificing productivity or
the level of service required of the operation.
Top 10 Principles of Material Handling (cont.)
Principle 4. Ergonomic Principle
Human capabilities and limitations must be recognized and respected in the
design of material handling tasks and equipment to ensure safe and effective
operations. Ergonomics is the science that seeks to adapt work or working
conditions to suit the abilities of the worker.
Principle 5. Unit Load Principle
Unit loads shall be appropriately sized and configured in a way which achieves
the material flow and inventory objectives at each stage in the supply chain. A
unit load is one that can be stored or moved as a single entity at one time, such as
pallet, container or tote, regardless of the number of individual items that make
up the load.
Principle 6. Space Utilization Principle
Effective and efficient use must be made of all available space. Space in material
handling is three dimensional and therefore is counted as cubic space.
Top 10 Principles of Material Handling (cont.)
Principle 7. System Principle
Material movement and storage activities should be fully integrated to form a
coordinated, operational system that spans receiving, inspection, storage,
production, assembly, packaging, unitizing, order selection, shipping,
transportation and the handling of returns.
Principle 8. Automation Principle
Material handling operations should be mechanized and/or automated where
feasible to improve operational efficiency, increase responsiveness, improve
consistency and predictability, decrease operating costs, and eliminate repetitive
or potentially unsafe manual labor.
Principle 9. Environmental Principle
Environmental impact and energy consumption should be considered as criteria
when designing or selecting alternative equipment and material handling
systems.
Top 10 Principles of Material Handling (cont.)
Principle 10. Life Cycle Cost Principle
A thorough economic analysis should account for the entire life cycle of all
material handling equipment and resulting system. Life cycle costs include all
cash flows that occur between the time the first dollar is spent to plan or procure
a new piece of equipment, or to put in place a new method, until that method
and/or equipment is totally replaced. Life cycle costs include capital investment,
installation, setup and equipment programming, training, system testing and
acceptance, operating (labor, utilities, etc.), maintenance and repair, reuse value,
and ultimate disposal.
Facility Layout
• A Layout problem may be to
– determine the location for a new machine,
– develop a new layout for an existing production plant,
– develop a layout for a new production plant,
– etc.
• A Layout problem may arises due to
– changes in the design of a product,
– addition or deletion of a product,
– change in the demand of a product,
– changes in the design of the process,
– addition or deletion of a process,
– replacement of equipment,
– etc.
Objectives of Facility Layout
• Minimize investment in equipment.
• Minimize production time.
• Minimize material handling cost.
• Maximize utilization of space.
• Maintain flexibility of arrangement and operation.
• Provide safety and comfort to employees.
Sequential Approach vs Integrated Approach
Sequential Approach :
Product
Design
Process
Design
Facility
Layout
Material
Handling
System Design
Production
Planning
Sequential Approach vs Integrated Approach
Integrated Approach :
Concurrent Engineering
Impressive results in cost, quality,
productivity, sales, customer
satisfaction, delivery time,
inventory levels, space + handling
requirements, building size, etc.
Terms of product, process,
scheduling and facility design
planners work with marketing,
purchasing, etc. Personnel
address the design process in
an integrated way.
Process
Design
Layout Design
+
Material Handling
System Design
Product
Design
Schedule
Design
Facility Layout Procedures
• Naddler’s Ideal System Approach (1961)
• Immer’s Basic Steps (1950)
• Apple’s Plant Layout Procedure (1977)
• Reed’s Plant Layout Procedure (1961)
• Muther’s Systematic Layout Planning (1961)
Naddler’s Ideal System Approach
The ideal system approach is based on the
following hierarchical approach toward
design:
1. Aim for the “theoretical ideal system.”
2. Conceptualize the “ultimate ideal
system.”
3. Design the “technologically workable
ideal system.”
4. Install the “recommended system.”
Theoretical ideal system
Ultimate ideal system
Technologically workable system
Recommended system
Present system
Immer’s Basic Steps
Immer described the analysis of a layout problem as follows: “This
analysis should be composed of three simple steps, which can be
applied to any type of layout problem. These steps are:
1. Put the problem on the paper.
2. Show lines of flow.
3. Convert flow lines to machine lines.”
Apple’s Plant Layout Procedure
Apple recommended that the following detailed sequence of steps be used in
designing a plant layout.
1. Procure the basic data.
11. Determine storage requirements
2. Analyze the basic data.
12. Plan service and auxiliary activities.
3. Design the productive process.
13. Determine space requirements.
4. Plan the material flow pattern.
14. Allocate activities to total space.
5. Consider the general material handling plan. 15. Consider building type
6. Calculate equipment requirements.
16. Consider master layouts.
7. Plan individual work stations.
17. Evaluate, adjust and check the layout.
8. Select specific material handling equipment. 18. Obtain approval.
9. Coordinate groups of related operations.
19. Install the layout.
10. Design activity relationships.
20. Follow up on implementation of the layout.
Reed’s Plant Layout Procedure
In “planning for and preparing the layout,” Reed recommended that the
following steps be taken in his “systematic plan of attach”:
1. Analyze the product to be produced.
2. Determine the process required to manufacture the product.
3. Prepare layout planning charts.
4. Determine work stations.
5. Analyze storage area requirements.
6. Establish minimum aisle widths.
7. Establish office requirements.
8. Consider personnel facilities and services.
9. Survey plant services.
10. Provide for future expansion.
Systematic Layout
Planning Procedure
(Muther 1961)
Information Gathering
Information about product, process and schedule is required.
The major effect of product design decisions is felt by the process designer, i.e., the material
used to make a part will influence processing decisions.
Design for automation programs have been developed that consider the impact of the design
of the product on the assembly process. Their primary thrusts are (1) dimensional reduction,
(2) parts elimination, and (3) parts standardization.For (1), the cost of assembly is reduced if
it occurs in a single dimension. The complexity of programming a robot increases
geometrically with the number of assembly dimensions.For (2), if more complex parts can
be produced, the number of parts can be reduced.
Schedule design decisions tell us how much to produce and when to produce. From the
market forecast, the production demand is determined and decisions about the production
rate are made.
Information Gathering
Information about product :
- Photographs about the product
- “Exploded” drawings
- Engineering drawings of individual parts
- Parts list
- Bill of materials (structure of product)
- Assembly chart
Gate Valve
“Exploded” Drawing of the Gate Valve
Engineering Drawing of the Gate Valve
Provide part
specifications and
dimensions in
sufficient detail for
manufacturing
Parts List of the Gate Valve
The parts list provides a
listing of the component
parts of a product. In
addition to make or buy
decisions, a parts list
includes part number, part
name, number of parts per
product, and drawing
references
Bill of Materials for the Gate Valve
Bill of materials is also
referred to as a structured
parts list since it includes all
of the information typically
included in the parts list, as
well as information
concerning the structure of
the product.
Assembly Chart I
It is an analog model of the assembly
process. Circles with a single link
denote basic components, circles with
several links denote assembly
operations/subassemblies, and squares
represent inspection operations.
Assembly Chart II
Information Gathering
Information about process :
- Route sheet (equipment and operation times)
- Precedence Diagram (prerequisite assembly steps before new
assembly step)
- Operation process chart (processing operations, assembly
operations, and inspections)
Route Sheet for one Component of the Gate Valve
Route sheet summarizes
whether a part will be
purchased or produced, how
the production of a part will
be achieved, what
equipment will be used, and
how long it take to perform
each operation.
Precedence Diagram for Assembling the Gate Valve
A precedence diagram establishes the prerequisite assembly steps
that must be completed before performing a given assembly step.
Operations Process Chart
By superimposing the route sheets and
the assembly chart, a chart results that
gives an overview of the flow within
the facility. This chart is the operations
process chart.
Information Gathering
Information about schedule :
- Production rate
- Product mix
- Market forecast (it is better to work with tomorrow’s data than
today’s data)
- Gantt charts
Gantt Project Planning Chart
Gantt project planning chart indicates the weekly operation schedule, the
estimated amount of time a particular operation will take, and the actual
amount of time that the particular operation has taken. The following chart
shows that the project is 1 week behind schedule.
Schedule Design
• Schedule design decisions tell us how much to produce and when to
produce.
Market
Forecast
Production
Demand
Product Mix
+
Production Rate
Production
Rate
Continuos or
Intermittent
Production
• Production schedules can be given in Gantt charts.
Number of
Machines