The P-H Microchip Co. needs to undertake a major maintenance and renovation program to overhaul and modernize its facilities for wafer fabrication. This project involves six activities (labeled A, B, . . . , F) with the precedence relationships shown in the following network.

The estimated durations and costs of these activities are shown below in the left column.

(a) Find the earliest times, latest times, and slack for each activity.
What is the earliest finish time for the completion of the project?
(b) Use the Excel template for PERT/Cost in your OR Courseware to display the budget and schedule of costs based on earliest start times for this project on a single spreadsheet.
(c) Repeat part (b) except based on latest start times.
(d) Use these spreadsheets to draw a figure like Fig. 22.15 to show the schedule of cumulative project costs when all activities begin at their earliest start times or at their latest start times.
(e) After 4 weeks, activity B has been completed (with an actual cost of $200,000), activity A is 50 percent completed (with an actual cost to date of $200,000), and activity D is 50 percent completed (with an actual cost to date of $210,000). Construct a PERT/Cost report after week 4. Where should the project manager focus her attention to improve cost performances?

START FINISH Activity Estimated Duration Estimated Cost 6 weeks 2 weeks 4 weeks 5 weeks 7 weeks 9 weeks $420,000 180,000 540,000 360,000 590,000 630,000