J0444
OPERATION MANAGEMENT
Desain Kapasitas
Universitas Bina Nusantara
Kapasitas
Outline
Kapasitas  hasil produksi atau jumlah
unit yang dapat ditahan, diterima,
disimpan, atau diproduksi oleh sebuh
fasilitas dalam suatu periode waktu
tertentu
Perencanaan Fasilitas
Facility Planning
Facility planning answers:
• How much long-range capacity is needed
• When more capacity is needed
• Where facilities should be located
(location)
• How facilities should be arranged (layout)
Proses Perencanaan Kapasitas
Capacity Planning Process
Forecast
Demand
Develop
Alternative
Plans
Quantitative
Factors
(e.g., Cost)
Compute
Rated
Capacity
Evaluate
Capacity
Plans
Qualitative
Factors
(e.g., Skills)
Compute
Needed
Capacity
Select Best
Capacity
Plan
Implement
Best Plan
Perencaanaan
Kapasitas
Berdasarkan
Types of Planning Over a
Horison Waktu
Time Horizon
Long Range
Planning
Intermediate
Range Planning
Add Facilities
Add long lead time equipment
Sub-Contract
Add Equipment
Add Shifts
*Limited options exist
Add Personnel
Build or Use Inventory
*
Short Range
Planning
Modify Capacity
*
Schedule Jobs
Schedule Personnel
Allocate Machinery
Use Capacity
Konsep dan Pengukuran Kapasitas
Definition and Measures of Capacity
Capacity:
Output maksimum sistem secara teoritis dalam
suatu periode waktu tertentu
Effective
capacity:
Kapasitas yang diharapkan dapat dicapai oleh
sebuah perusahaan dengan baruran produk,
metode penjadwalan, dan standar kualitas
yang diberikan.
Utilization:
Output aktual sebagai persentase kapasitas desain
Efficiency:
Output aktual sebagai persentase kapasitas
efektif
Actual or Expected Output
Actual (or Expected) Output =
(Effective Capacity)(Efficiency)
Utilisasi
Utilization
Measure of planned or actual capacity usage of a
facility, work center, or machine
Utilization
=
=
Actual Output
Design Capacity
Planned hours to be used
Total hours available
Efisiensi
Efficiency
Measure of how well a facility or
machine is performing when used
Efficiency
Actual output
=
Effective Capacity
Actual output in units
=
Standard output in units
Average actual time
=
Standard time
Imlikasi terhadap Perubahan Kapasitas
Implications of Capacity Changes
Changes in:
•
Sales
•
Cash flow
•
Quality
•
Supply chain
•
Human resources
•
Maintenance
Special
Requirements
Making
Special Requirements
for for
Making
GoodGood
Capacity
Decisions
Capacity
Decisions
• Forecast demand accurately
• Understanding the technology and
capacity increments
• Finding the optimal operating level
(volume)
• Build for change
Struktur Biaya untuk Roadside Motel
Cost Structure for a Roadside Motel
25 room
roadside motel
50 room
roadside motel
Economies of
Scale
75 room
roadside motel
Diseconomies
of Scale
Number of Rooms
Strategies
for for
Matching
Strategies
MatchingCapacity
Capacity to
to Demand
Demand
1. Making staffing changes (increasing
or decreasing the number of
employees)
2. Adjusting equipment and processes
– which might include purchasing
additional machinery or selling or
leasing out existing equipment
3. Improving methods to increase
throughput; and/or
4. Redesigning the product to facilitate
more throughput
Pendekatan
Terhdap
Approaches
to Ekspansi
Capacity Kapasitas
Expansion
Expected Demand
Expected Demand
New Capacity
Demand
Demand
New Capacity
Time in Years
Time in Years
Capacity leads demand with an incremental expansion
Capacity leads demand with a one-step expansion
Expected Demand
Expected Demand
New Capacity
Demand
Demand
New Capacity
Time in Years
Capacity lags demand with an incremental expansion
Time in Years
Attempts to have an average capacity, with an
incremental expansion
Approaches to Capacity Expansion
Expected Demand
Demand
New Capacity
Time in Years
Capacity leads demand with an incremental expansion
Approaches to Capacity Expansion
Expected Demand
Demand
New Capacity
Time in Years
Capacity leads demand with a one-step expansion
Breakeven Analysis
• Technique for evaluating process &
equipment alternatives
• Objective: Find the point ($ or units) at which
total cost equals total revenue
• Assumptions
– Revenue & costs are related linearly to
volume
– All information is known with certainty
– No time value of money
Break-Even Analysis
• Fixed costs: costs that continue
even if no units are produced:
depreciation, taxes, debt, mortgage
payments
• Variable costs: costs that vary with
the volume of units produced: labor,
materials, portion of utilities
Breakeven Chart
Total revenue line
Profit
Cost in Dollars
Breakeven point
Total cost = Total revenue
Total cost line
Variable cost
Loss
Fixed cost
Volume (units/period)
Decision Tree and Capacity Decision
-$14,000
Market favorable (0.4)
Market unfavorable (0.6)
$18,000
Market favorable (0.4)
Market unfavorable (0.6)
$13,000
Market favorable (0.4)
Market unfavorable (0.6)
$100,000
-$90,000
$60,000
-10,000
-5,000
$40,000
$0
Strategy Driven Investment
• Select investments as part of a coordinated
strategic plan
• Choose investments yielding competitive
advantage
• Consider product life cycles
• Include a variety of operating factors in the
financial return analysis
• Test investments in light of several revenue
projections
Net Present Value
F = future value
P = present value
F
P
N
I = interest rate
(i  1)
N = number of years
NPV in a More Convenient Form
Present value of $1.00
P
Year
F
(i  1)
N
5%
6%
7%
8%
1
0.952
0.943
0.935
0.857
2
0.907
0.890
0.873
0.857
3
0.864
0.840
0.816
0.794
4
0.823
0.792
0.763
0.735
5
0.784
0.747
0.713
0.681
6
0.746
0.705
0.666
0.630
7
0.711
0.665
0.623
0.583
8
0.677
0.627
0.582
0.540
9
0.645
0.592
0.544
0.500
P  FX
1
where X 
N
(i  1 )
Present Value of an Annuity (S)
• X = Factor from Table
• S = present value of a
series of uniform
annual receipts
• R = receipts that are
received every year
for the life of the
investment
S  RX
Year
5%
6%
7%
8%
1
0.952
0.943
0.935
0.926
2
1.859
1.833
1.808
1.783
3
2.723
2.673
2.624
2.577
4
3.546
3.465
3.387
3.312
5
4.329
4.212
4.100
3.993
6
5.076
4.917
4.766
4.623
7
5.786
5.582
5.389
5.206
8
6.843
6.210
5.971
5.747
9
7.108
6.802
7.024
6.247