Question

tii) Speed delivery of special accessories by 3 days CASE STUDIES Southwestern University: (A) Southwesterm University (SWU), a large state college in Stephenville season opening game. The contractor, Hill Construction (Bob Hill Texas, 30 miles southwest of the Dallas/Fort Worth metroplex, being an alumnus, of course), signed his contract. Bob Hill looked at enrolls close to 20,000 stadents. In a typical town-gown relationship. the tasks his engineers had outlised and looked President Wiseer in the school is a dominant force in the small city, with more students the cye. "I guarantee the team will be able to take the field on sched- during fall and spring than permanent residents. ule next year. he sald with a sense of coafidence. "1 sure hope so, A longtime football powertiouse, swU is a member of the Big replied Wisner. The contract penalty of $10,000 per day for running Eleven conference and is usually in the top 20 in college football late is nothing compared to what Coach Flamm will do to you if our rankings. To bolster its chances of reaching the elusive and long opening game witch Pemn State is delayed or canceled." Hill, sweat desired number-one ranking, in 2006, SWU hired the legendary Phil ing slightly, did not need to respond. In football-crary Texas, Hill Flamm as its head coach. Construction would be mad if the 270-day target was missed. One of Flamm's demands on joining SWU had been a new sta- dium. With attendance increasing, SWU administrasors began to face the issue head.。. After 6 months of gudy, much political arm wres- tling, and some serlous financial analysis, Dr. Joel Wisner, presides of Southwestern University, had reached a decision to expand the capacity at its on-campus stadium. Back in his office, Hill again reviewed the data (see Table 6) and noted that optimistic time estimates can be used as crash times. He then gathered his foremen "Folks, if we're not 75% sore we'll finish this stadiom in less than 270 days,I want this project crashed! Give me the cost figures for a target date of 250 days-also for 240 days.I want to be early, not just on timef Adding thousands of seats, including dozens of luxury skyboxes, would not please everyone. The influential Flarmm had argued the Discussion Questions nced for a first-class stadium, one with built-in dormitory rooms for 1. Develop a network drawing for Hill Constraction and determise his players and a palatial office appropriate for the cosch of a fuoure NCAA champion team. But the decision was made, and everyone, 2. What is the probablity of finishing ia 270 days? including the coach, would learn to live with it. the critical path. How long is the project expected to take? 3. If it is necessary to crash to 250 or 240 days, bow would Hill do The job now was to get construction going immediately after the 2012 season ended. This woold allow exactly 270 days until the 2013 so, and at what costs? As noted in the case, assume that optimistic time estimates can be used as crash times. ABLE 6 Southwestern University Project IME ESTIMATES (DAYS PREDECESSORIS) OPTIMISTIC MOST LIKELY PESSIMISTIC CRASH COSTIDAY 1,500 3,500 4,000 1,900 9,500 ACTIVITY DESCRIPTION Bonding insurance, tax structuring Foundation, concrese footings for boses Upgrading skybox stadium seating Upgrading walkways, stairwells, elevators interlor wiring lathes rspection approvals 0.1 0.1 D, F 2.500 2,000 2,000 Hardware ACimetal workings 0.1 0.1 500 Final detail workidleanup

Answer 1

Activi Optimistic Most likel Pessimistic Expected time B2+4*C2+D2)/6 (B3+4*C3+D3)/6 B4+4*C4+D4)/6 B5+4*C5+D5)/6 (B6+4*C6+D6)/6 B7+4*C7+D7)/6 B8+4*C8+D8)/6 B9+4*C9+D9)/6 B 10+4*C10+D10)/6 (B11+4*C11+D11)/6 (B12+4*C12+D12)/6 (B13+4*C13+D13)/6 Variance ((D2-B2)/6)A2 ((D3-B3)/6)A2 (D4-B4)/61A2 ((D5-B5)/6)A2 ((D6-B6)/6)A2 ((D7-B7)/6)A2 ((D8-B8)/6)A2 ((D9-B9)/6)A2 30 30 25 0.1 25 10 100 100 35 0.1 35 30 30 0.1 30 6 D10-B10)/6 A2 D11-B11)/6 A2 D12-B12)/6 A2 D13-B13)/6 A2 10 25 10 0.1 25 12 0.1 0.1 13 14

Aciuy Ogeinetec oected tines Vanance 20 20 30 65 60 30 60 65 섹) a) 100 100 35 0.1 35 30 60 12 0.1 60 100.0000 69.4444 30 30 0.1 30 20 136.1111 2.7778 0.0000 2.7778 30 0.1 30 20 30 10 0.1 30 1 0.1 10) 20 44.4444 0.4444 O.xXX) 44.4444 10 0.1 0.1 2

e(36)2 one 449-9 30 h (30) 30 9S H (20) 2ヂ 210 230 2OD 229-9 2bo 230 Es ld
The completion time is 260

The critical path is A-C-D-G-H-I-L as the floats of all these activities are Zero

b)

To find the probability we need to find Z value

Z= (Expected time- Critical path time)/ Stddevcp

Expected time = 270

Critical path time = 260

Stddevcp is standard deviation along critical path

Stddevcp = Sqrt(Vcp)

Vcp- variance along critical path which is sum of variances of critical activities

Vcp = 11.1111+ 69.4444+136.1111+2.7778+11.1111+44.4444+44.4444= 319.4444

Stddevcp= Sqrt(319.4444) = 17.873

Z= (270-260)/17.873

Z= 0.5595

Corresponding probability is 0.712 which is 71.2%

c) If project has to be reduced to 250 units , then first A has to be crashed for 10 days at a cost of 1500*10 = 15000

Expected time is 30 and optmistic is 20. Therefore a maximum of (30-20)=10 days can be crashed for A,

If the project has to be further crashed to 240, then next least cost activity D has to be crashed at 10*1900 = 19000

Therefore total cost for crashing project to 240 days = 15000+19000 = 34000

The critical activities have to be crashed first. The activities with least crash cost per day are crashed first.