The RELIABLE CONSTRUCTION COMPANY has just made the winning bid of $5.4 million to construct a new plant for a major manufacturer. The manufacturer needs the plant to go into operation within a year. Therefore, the contract includes the following provisions:
• A penalty of $300,000 if Reliable has not completed construction by the deadline 47 weeks from now.
• To provide additional incentive for speedy construction, a bonus of $150,000 will be paid to Reliable if the plant is completed within 40 weeks.
Reliable is assigning its best construction manager, David Perty, to this project to help ensure that it stays on schedule. He looks forward to the challenge of bringing the project in on schedule, and perhaps even finishing early. However, since he is doubtful that it will be feasible to finish within 40 weeks without incurring excessive costs, he has decided to focus his initial planning on meeting the deadline of 47 weeks.
Mr. Perty will need to arrange for a number of crews to perform the various construction activities at different times. Table 10.1 shows his list of the various activities. The third column provides important additional information for coordinating the scheduling of the crews.
For any given activity, its immediate predecessors (as given in the third column of Table 10.1) are those activities that must be completed by no later than the starting time of the given activity.
TABLE 10.1 Activity list for the Reliable Construction Co. project
Activity Activity Description Immediate Predecessors Estimated Duration

A Excavate 2 weeks
B Lay the foundation A 4 weeks
C Put up the rough wall B 10 weeks
D Put up the roof C 6 weeks
E Install the exterior plumbing C 4 weeks
F Install the interior plumbing E 5 weeks
G Put up the exterior siding D 7 weeks
H Do the exterior painting E,G 9 weeks
I Do the electrical work C 7 weeks
J Put