MOORE HOUSING CONTRACTORS If a house is not completed within this time frame, it wants to be able to charge the contractor a penalty. Mary and Sandy Moore, the president and vice president, respectively, Moore Housing Contractors is negotiating a deal with of Moore Contractors, are concerned about the prospect of Countryside Realtors to build six houses in a new develop- a penalty charge. They want to be very confident that they ment. Countryside wants Moore Contractors to start in late can meet the deadline for a house before they enter into any winter or early spring, when the weather begins to moder- kind of agreement with a penalty involved. (If there is a ale, and build on through the summer and into the fall. The reasonable likelihood that they cannot finish a house within summer months are an especially busy time for the realty 45 days, they want to increase their bid to cover potential company, and it believes it can sell the houses almost as penalty charges.) soon as they are ready, and maybe even before. The houses The Moores are experienced home builders, so it was all have similar floor plans and are of approximately equal not difficult for them to list the activities involved in build- size: only the exteriors are noticeably different. The comple- ing a house or to estimate activity times. However, they tion time is so critical for Countryside Realtors that it is made their estimates conservatively and tended to increase insisting that a project management network accompany the their pessimistic estimates to compensate for the possibility contractor's bid for the job, with an estimate of the comple- of bad weather and variations in their workforce. A list of tion time for a house. The realtor also needs to be able to the activities involved in building a house and the activity plan its offerings and marketing for the summer. It wants time estimates follow. cach house to be completed within 45 days after it is started. Time (days) Activity Activity Description Activity Predecessor a m b Excavation, pour footers 3 4 6 h Lay foundation 5 C Frame and roof 4 d Lay drain tiles 4 Sewer (floor) drains b 1 3 Install insulation C 5 Pour basement floor e h Rough plumbing, pipes SUN W A W A N N Install windows 4 Rough electrical wiring 4 K Install furnace, air conditioner Exterior brickwork 10 m Install plasterboard, mud. plaster j. h. k 12 n Roof shingles, flashing 6 Attach gutter, downspouts n P Grading d, o Lay subflooring m 6 r Lay driveway, walks, landscape P 10 Finish carpentry 4 ANHWAWN 12 Kitchen cabinetry, sink, and appliances 4 8 Bathroom cabinetry, fixtures 6 V Painting (interior and exterior) 6 10 W Finish wood floors, lay carpet V. S 5 Final electrical, light fixtures V 4 Develop a CPM/PERT network for Moore Housing b. Indicate which project activities Moore Housing Contractors and determine the probability that the Contractors should be particularly diligent to keep on company can complete a house within 45 days, Does schedule by making sure workers and materials are it appear that the Moores might need to increase their always available. Also indicate which activities the bid to compensate for potential penalties? company might shift workers from as the need arises