Question

The following data were obtained from a project to expand a warehouse:

Activity

Duration

Predecessors

Resources/cost

A

2 weeks

--

1 Excavator/$800

day

B

3 weeks

--

1 Excavator/$800

day

C

2 weeks

--

1 Concrete

Mixer/$250 day

D

3 weeks

A

1 Crane/$1,000 day

E

2 weeks

C

1 High-lift/$500

day

F

1 week

B,D

1 Crane/$1,000 day

The contractor has only one machine of each type available at the above costs, and operations cannot be split. Additional equipment can be rented at a 50% cost premium if needed.

a.	Identify any resource conflicts in the above project. State

the activities involved, the time frame of the conflict(s), the resources in conflict and the quantity of resource involved.

b.	What is the least cost method of resolving the conflict(s),

assuming the project duration must not be extended? What additional cost, if any, will be incurred? (Note that the job is operating a standard 5 day week).

Answer 1

The two activities A and B need excaavator for 2 and 3 days respectively. since these activities coincide, they can not run together. In this way, Actvity A can start first, and B can start only when A ends. Activity B has float of 2 days so it can manage to start when A is complete. Activity D and F share a resource ( crane) but come one after other, so there is no conflict.

If the project is to be completed in 6 days, the activities finishing in 5 days will be A, B,D,C and E. F will start at the start of day 6. If the company keeps the crane in continuation , it will have to keep it on Saturday And Sunday also, incurrring a cost of 2000 extra. If it is possivle to re hire the crane on Monday, there will be no extra cost.