5–1 Operations and Supply Chain Management CHASE | SHANKAR | JACOBS 14 e
5–2
StrategicCapacityManagement
Chapter FiveCopyright © 2014 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill/Irwin
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Learning Objectives• LO5–1: Explain what capacity
management is and why it is strategically important.
• LO5–2: Exemplify how to plan capacity.
• LO5–3: Evaluate capacity alternatives using decision trees.
• LO5–4: Compare capacity planning in services to capacity planning in manufacturing
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ed.Economies of Scale
Made of Steel• The Economics of Very Big Ships• Economy of Container Ships
– Allows a T-shirt made in China to be sent to the Netherlands for just 2.5 cents.
– The Eleonora Maersk and the other seven ships in her class are among the largest ever built:
– Almost 400 m long, or the length of four soccer fields, and another half-field across.
– The ships can carry 7,500 or so 40-foot containers, each of which can hold 70,000 T-shirts.
• On this voyage, the Eleonora was carrying supplies for Europe’s New Year celebrations: 1,850 tons of fireworks, including 30 tons of gunpowder.
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ed.Capacity Management in
Operations• Capacity – the ability to hold, receive,
store, or accommodate
• In business, viewed as the amount of output that a system is capable of achieving over a specific period of time
• Capacity management needs to consider both inputs and outputs
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ed.Capacity Planning
Time Durations• Greater than one year
Long range
• Monthly or quarterly plans covering the next 6 to 18 months
Intermediate range
• Less than one month
Short range
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ed.Strategic Capacity
Planning• Determining the overall level of
capacity-intensive resources that best supports the company’s long-range competitive strategy– Facilities– Equipment– Labor force size
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ed.Capacity Planning
Concepts• Capacity utilization rate – a measure of how
close the firm is to its best possible operating level
• Economies of scale – the idea that as a planet gets larger and volume increases, the average cost per unit tends to drop
• Diseconomies of scale – at some point, the plant becomes too large and average cost per unit begins to increase
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ed.Capacity Planning
Concepts• Capacity focus – the idea that a production
facility works best when it is concentrated on a limited set of production objectives– Focused factory or plant within a plant (PWP) concept
• Capacity flexibility – the ability to rapidly increase or decrease product levels or the ability to shift rapidly from one product or service to another– Comes from the plant, processes, and workers or
from strategies that use the capacity of other organizations
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Capacity Flexibility•Ability to quickly adapt to change•Zero-changeover time
Flexible Plants
•Flexible manufacturing systems•Simple, easily set up equipment
Flexible Processes
•Ability to switch from one kind of task to another quickly•Multiple skills (cross training)
Flexible Workers
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ed.Considerations in Changing
CapacityMaintaining System Balance
• Similar capacities desired at each operation• Manage bottleneck operations
Frequency of Capacity Additions• Cost of upgrading too frequently• Cost of upgrading too infrequently
External Sources of Capacity• Outsourcing• Sharing capacity
Decreasing Capacity• Temporary reductions• Permanent reductions
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Frequent versus Infrequent Capacity
Expansions
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ed.Determining Capacity
Requirements
Use forecasting to predict sales for
individual products
Calculate labor and equipment requirements to meet forecasts
Project labor and equipment
availability over the planning
horizon
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Example 5.1—Determining Capacity
Requirements• Stewart Company produces two
flavors of salad dressing.– Paul’s and Newman’s
• Each is available in bottles and single-serving bags.
• What are the capacity and labor requirements for the next five years?
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ed.Determining Capacity
Requirements
Year1 2 3 4 5
Paul’sBottles (000s) 60 100 150 200 250Plastic bags (000s)
100 200 300 400 500
Newman’sBottles (000s) 75 85 95 97 98Plastic bags (000s)
200 400 600 650 680
Step 1: Use forecasting to predict sales for individual products
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ed.Determining Capacity
Requirements
Bottling Operation Bagging Operation
Year1 2 3 4 5
Bottles (000s) 135 185 245 297 348Plastic bags (000s) 300 600 900 1050 1180
Step 2: Calculate equipment and labor requirements
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ed.Determining Capacity
RequirementsYear
1 2 3 4 5
Plastic Bag Operation
Percentage capacity utilized 24 48 72 84 94
Machine requirement 1.2 2.4 3.6 4.2 4.7Labor requirement 3.6 7.2 10.8 12.6 14.1
Bottle Operation
Percentage capacity utilized 30 41 54 66 77
Machine requirement 0.9 1.23 1.62 1.98 2.31Labor requirement 1.8 2.46 3.24 3.96 4.62
Step 3: Project equipment and labor availabilities
Excel: Capacity Requirements
For the Excel template visit www.mhhe.com/sie-chase14e
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ed.Decision Trees for Capacity
Analysis• A decision tree is a schematic model of the
sequence of steps in a problem – including the conditions and consequences of each step.
• Decision trees help analysts understand the problem and assist in identifying the best solution.
• Decision tree components include the following:– Decision nodes – represented with squares– Chance nodes – represented with circles– Paths – links between nodes
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ed.Example 5.2: Decision
Trees• The owner of Hackers Computer Store is evaluating
three options – expand at current site, expand to a new site, do nothing.
• The decision process includes the following assumptions and conditions.– Strong growth has a 55% probability– New site cost is $210,000
Payoffs: strong growth = $195,000; weak growth = $115,000
– Expanding current site cost is $87,000 (in either year 1 or 2) Payoffs: strong growth = $190,000; weak growth =
$100,000– Do nothing
Payoffs: strong growth = $170,000; weak growth = $105,000
5–20
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ed.Example 5.2: Decision
Trees• Calculate the value of each
alternative
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ed.Example 5.2: Decision
Trees• Diagram the problem chronologically
Decision
Events
Decision
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ed.Example 5.2: Decision
Trees• Calculate value of each branch
$765,000
$365,000
$863,000
$413,000
$843,000
$850,000
$525,000
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ed.Example 5.2
• Work backwards to calculate the value of each decision/event
$765,000
$365,000
$863,000
$413,000
$843,000
$850,000
$525,000
$660,500
$703,750 Do nothing = $850,000
Do nothing = $703,750
Do nothing has higher value than expand, so choose to do nothing
Do nothing has higher value than expand or move, so choose to do nothing
5–24
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ed.Example 5.2: Decision
Trees• Decision tree analysis with net present
value calculations
Excel: Decision Trees
For the Excel template visit www.mhhe.com/sie-chase14e
5–25
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ed.Planning Service
CapacityManufacturing Capacity
Goods can be stored for later use.
Goods can be shipped to other locations.
Volatility of demand is relatively low.
Service Capacity
Capacity must be available when service is needed –
cannot be stored.
Service must be available at customer demand point.
Much higher volatility is typical.
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ed.Capacity Utilization and
Service Quality• The relationship between service capacity
utilization and service quality is critical.– Utilization is measured by the portion of time
servers are busy.
• Optimal levels of utilization are context specific.– Low rates are appropriate when the degree of
uncertainty (in demand) is high and/or the stakes are high (e.g., emergency rooms, fire departments).
– Higher rates are possible for predictable services or those without extensive customer contact (e.g., commuter trains, postal sorting).
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Service Quality• Rate of service utilization and service
quality are directly linked.Arrivals exceed services – many customers are never served
Sufficient capacity to provide quality service
Service quality declines – disruptions or high arrival levels lead to long wait times