Chapter 5

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5
Capacity Planning
For Products and
Services
McGraw-Hill/Irwin
Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved.
Learning Objectives





Explain the importance of capacity
planning.
Discuss ways of defining and measuring
capacity.
Describe the determinants of effective
capacity.
Discuss the major considerations related to
developing capacity alternatives.
Briefly describe approaches that are useful
for evaluating capacity alternatives
5-2
Capacity Planning
 Capacity is the upper limit or ceiling on
the load that an operating unit can
handle.
 Capacity also includes



Equipment
Space
Employee skills
 The basic questions in capacity handling
are:



What kind of capacity is needed?
How much is needed?
When is it needed?
5-3
Importance of Capacity Decisions
1. Impacts ability to meet future demands
2. Affects operating costs
3. Major determinant of initial costs
4. Involves long-term commitment
5. Affects competitiveness
6. Affects ease of management
7. Globalization adds complexity
8. Impacts long range planning
5-4
Capacity
 Design capacity

maximum output rate or service capacity an
operation, process, or facility is designed for
 Effective capacity

Design capacity minus allowances such as
personal time, maintenance, and scrap
 Actual output

rate of output actually achieved--cannot
exceed effective capacity.
5-5
Efficiency and Utilization
Actual output
Efficiency =
Effective capacity
Actual output
Utilization =
Design capacity
Both measures expressed as percentages
5-6
Efficiency/Utilization Example
Design capacity = 50 trucks/day
Effective capacity = 40 trucks/day
Actual output = 36 units/day
Actual output
=
36 units/day
Efficiency =
=
90%
Effective capacity
Utilization =
72%
Actual output
Design capacity
40 units/ day
=
36 units/day
50 units/day
=
5-7
Determinants of Effective
Capacity








Facilities
Product and service factors
Process factors
Human factors
Policy factors
Operational factors
Supply chain factors
External factors
5-8
Strategy Formulation




Capacity strategy for long-term demand
Demand patterns
Growth rate and variability
Facilities
 Cost of building and operating
 Technological changes
 Rate and direction of technology changes
 Behavior of competitors
 Availability of capital and other inputs
5-9
Key Decisions of Capacity
Planning
1. Amount of capacity needed
•
Capacity cushion (100% - Utilization)
2. Timing of changes
3. Need to maintain balance
4. Extent of flexibility of facilities
Capacity cushion – extra demand intended to offset uncertainty
5-10
Steps for Capacity Planning
1. Estimate future capacity requirements
2. Evaluate existing capacity
3. Identify alternatives
4. Conduct financial analysis
5. Assess key qualitative issues
6. Select one alternative
7. Implement alternative chosen
8. Monitor results
5-11
Forecasting Capacity
Requirements
 Long-term vs. short-term capacity needs
 Long-term relates to overall level of capacity
such as facility size, trends, and cycles
 Short-term relates to variations from
seasonal, random, and irregular fluctuations
in demand
5-12
Calculating Processing
Requirements
Standard
processing time
per unit (hr.)
Product
Annual
Demand
Processing time
needed (hr.)
#1
400
5.0
2,000
#2
300
8.0
2,400
#3
700
2.0
1,400
5,800
If annual capacity is 2000 hours, then we need three machines to handle the
required volume: 5,800 hours/2,000 hours = 2.90 machines
5-13
Planning Service Capacity
 Need to be near customers
 Capacity and location are closely tied
 Inability to store services
 Capacity must be matched with timing of
demand
 Degree of volatility of demand
 Peak demand periods
5-14
In-House or Outsourcing
Outsource: obtain a good or service
from an external provider
1.
2.
3.
4.
5.
6.
Available capacity
Expertise
Quality considerations
Nature of demand
Cost
Risk
5-15
Developing Capacity Alternatives
1.Design flexibility into systems
2.Take stage of life cycle into account
3.Take a “big picture” approach to capacity
changes
4.Prepare to deal with capacity “chunks”
5.Attempt to smooth out capacity
requirements
6.Identify the optimal operating level
5-16
Bottleneck Operation
Figure 5.2
Machine #1
Machine #2
Bottleneck operation: An operation
in a sequence of operations whose
capacity is lower than that of the
other operations
10/hr
10/hr
Machine #3
Bottleneck
Operation
30/hr
10/hr
Machine #4
10/hr
5-17
Bottleneck Operation
Bottleneck
Operation 1
20/hr.
Operation 2
10/hr.
Operation 3
15/hr.
10/hr.
Maximum output rate
limited by bottleneck
5-18
Economies of Scale
 Economies of scale
 If the output rate is less than the optimal level,
increasing output rate results in decreasing
average unit costs
 Diseconomies of scale
 If the output rate is more than the optimal
level, increasing the output rate results in
increasing average unit costs
5-19
Optimal Rate of Output
Figure 5.4
Average cost per unit
Production units have an optimal rate of output for minimal cost.
Minimum average cost per unit
Minimum
cost
0
Rate of output
5-20
Economies of Scale
Figure 5.5
Average cost per unit
Minimum cost & optimal operating rate are
functions of size of production unit.
0
Small
plant
Medium
plant
Large
plant
Output rate
5-21
Evaluating Alternatives
 Cost-volume analysis
 Break-even point
 Financial analysis
 Cash flow
 Present value
 Decision theory
 Waiting-line analysis
5-22
Cost-Volume Relationships
Amount ($)
Figure 5.6a
Fixed cost (FC)
0
Q (volume in units)
5-23
Cost-Volume Relationships
Amount ($)
Figure 5.6b
0
Q (volume in units)
5-24
Cost-Volume Relationships
Amount ($)
Figure 5.6c
0
BEP units
Q (volume in units)
5-25
Break-Even Problem with Step
Fixed Costs
Figure 5.7a
3 machines
2 machines
1 machine
Quantity
Step fixed costs and variable costs.
5-26
Break-Even Problem with Step
Fixed
Costs
Figure 5.7b
$
BEP
3
TC
BEP2
TC
3
TC
2
1
Quantity
Multiple break-even points
5-27
Assumptions of Cost-Volume
Analysis
1.One product is involved
2.Everything produced can be sold
3.Variable cost per unit is the same
regardless of volume
4.Fixed costs do not change with volume
5.Revenue per unit constant with volume
6.Revenue per unit exceeds variable cost
per unit
5-28
Financial Analysis
 Cash Flow - the difference between
cash received from sales and other
sources, and cash outflow for labor,
material, overhead, and taxes.
 Present Value - the sum, in current
value, of all future cash flows of an
investment proposal.
5-29
Decision Theory
 Helpful tool for financial comparison of
alternatives under conditions of risk or
uncertainty
 Suited to capacity decisions
 See Chapter 5 Supplement
5-30
Waiting-Line Analysis
 Useful for designing or modifying service
systems
 Waiting-lines occur across a wide variety of
service systems
 Waiting-lines are caused by bottlenecks in
the process
 Helps managers plan capacity level that will
be cost-effective by balancing the cost of
having customers wait in line with the cost of
additional capacity
5-31
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