Office Automation Inc., developed a proposal for implementing a software system that will standardize the accounts payable function by automatically issuing an electronic payment upon receipt of the vendor invoice. Contained in the proposal is a list of activities that must be accomplished to complete the project. The following table contains relevant information about the activities.

Time (weeks)Cost ($1,000s)ActivityDescriptionImmediate PredecessorNormalCrashNormalCrashAPlan needs 1083070BOrder equipmentA86120150CInstall equipmentB107100160DSet up training labA764050EConduct training courseD1085075FTest systemC, E3360

(a)

Develop a project network.

A project network with 8 activities and 8 directed arcs is shown.

• Activity Start is connected to activity A.
• Activity A is connected to activity B and to activity C.
• Activity B is connected to activity D.
• Activity C is connected to activity E.
• Activity D is connected to activity F.
• Activity E is connected to activity F.
• Activity F is connected to activity Finish.
• Activity Finish has no arcs directed to other activities.

A project network with 8 activities and 8 directed arcs is shown.

• Activity Start is connected to activity A.
• Activity A is connected to activity B and to activity C.
• Activity B is connected to activity E.
• Activity C is connected to activity D.
• Activity D is connected to activity F.
• Activity E is connected to activity F.
• Activity F is connected to activity Finish.
• Activity Finish has no arcs directed to other activities.

A project network with 8 activities and 8 directed arcs is shown.

• Activity Start is connected to activity A.
• Activity A is connected to activity B and to activity D.
• Activity B is connected to activity E.
• Activity C is connected to activity F.
• Activity D is connected to activity C.
• Activity E is connected to activity F.
• Activity F is connected to activity Finish.
• Activity Finish has no arcs directed to other activities.

A project network with 8 activities and 8 directed arcs is shown.

• Activity Start is connected to activity A.
• Activity A is connected to activity B and to activity D.
• Activity B is connected to activity C.
• Activity C is connected to activity F.
• Activity D is connected to activity E.
• Activity E is connected to activity F.
• Activity F is connected to activity Finish.
• Activity Finish has no arcs directed to other activities.

(b)

Develop an activity schedule.

ActivityEarliest StartLatest StartEarliest FinishLatest FinishSlackA B C D E F

(c)

What are the critical activities? (Enter your answers as a comma-separated list.)

A,B,C,D,E,F (wrong)

What is the expected project completion time (in weeks)?

29 weeks (wrong)

(d)

Assume that the company wants to complete the project in six months or 26 weeks. What is the amount of crash time (in weeks) for each activity that minimizes cost?

(A, B, C, D, E) =

8,6,7,6,8 (wrong)

(e)

Develop an activity schedule for the crashed project.

ActivityEarliest StartLatest StartEarliest FinishLatest FinishSlackA B C D E F

(f)

What added project cost (in thousands of dollars) is required to meet the six-month completion time?

112.5 thousands of dollars