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Resource Allocation. BBUS541 Hiroshi Ochiumi. Introduction. Projects Compete With One Another for Resources resources that are not consumed resources that are consumed Goal of Resource Allocation is to Optimize Use of Limited Supply Requires making trade-offs time constrained
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Resource Allocation BBUS541 Hiroshi Ochiumi
Introduction • Projects Compete With One Another for Resources • resources that are not consumed • resources that are consumed • Goal of Resource Allocation is to Optimize Use of Limited Supply • Requires making trade-offs • time constrained • resource constrained
Expediting a Project BBUS541 Hiroshi Ochiumi
Expediting a Project • Time-Cost Trade-off Model • A model that develops the relationship between direct project costs, indirect costs, and time to complete the project by minimizing the sum of direct and indirect costs. • Crash Costs • The additional costs of an activity when time to complete it is shortened.
Minimum Cost Scheduling Step 1:Prepare CPM-type network diagram. a. Normal cost (NC) b. Normal time (NT) c. Crash time (CT) d. Crash Cost (CC) Step 2: Determine the cost per unit of time to expedite (or crash) each activity. Step 3: Compute the critical path. Step 4: Shorten the critical path at the least cost. Step 5: Plot project direct, indirect, and total-cost curves and find the minimum-cost schedule.
Example 1 5 B 3 2 2 7 D A 7 10 ES=0 EF=2 4 C 2 6
Critical Path? • A-B-D 2+5+3=10 • A-C-D 2+4+3=9
“Crash” A-B-D path by 1 • Where exactly do we want to crash?
Network Diagram 5 Cost +2 B 2 2 2 7 D A 7 9 ES=0 EF=2 4 C 2 6
Critical Path? • A-B-D 2+5+2=9 • A-C-D 2+4+2=8
Crash A-B-D by 1 • Where do we want to crash?
Network Diagram 5 Cost +2+2 B 1 2 2 7 D A 7 8 ES=0 EF=2 4 C 2 6
Critical Path? • A-B-D 2+5+1=8 • A-C-D 2+4+1=7
Crash A-B-D by 1 • Where do we want to crash?
Network Diagram 4 Cost +2+2+3 B 1 2 2 6 D A 6 7 ES=0 EF=2 4 C 2 6
Critical Path? • A-B-D 2+4+1=7 • A-C-D 2+4+1=7
Crash both paths by 1 • Where do we want to crash? • Do we want to crash C?
Network Diagram 4 Cost +2+2+3+4 B 1 1 1 5 D A 5 6 ES=0 EF=1 4 C 1 5
Critical Path? • A-B-D 1+4+1=6 • A-C-D 1+4+1=6
Crash both paths by 1 • Where do we want to crash? • Do we want to crash C only?
Network Diagram 3 Cost +2+2+3+4+3+2 B 1 1 1 4 D A 4 5 ES=0 EF=1 3 C 1 4
Cost per day to Expedite • Can we continue?
Example 2 • Can we use Excel Solver?
Using Excel Solver to Crash a Project • Objective • minimize crashing costs • Decision Variables • amount to crash activities • time events occur, or EST’s • Constraints • amount each activity can be crashed • precedence relationships • complete project by specified time • nonnegativity
Resource Loading BBUS541 Hiroshi Ochiumi
Resource Loading • Amount of specific resources that are scheduled for use on specific activities or projects at specific times. • Usually a list or table.
Resource Leveling BBUS541 Hiroshi Ochiumi
Last week • We evaluated project durations only in terms of time. • We have to consider when and for what purposes: • People • Equipment • Material • Facilities • are used.
Resource Leveling • Overallocation must be resolved. • Move activities so that resources do not exceed their capacities. • Without extending the project duration if possible