CASE 11-1: EASING IRA’S IRE
Question 1: Arrange the tasks shown in Exhibit 11-A in a network or PERT chart.
A chart with three paths results. They, and their completion times, are:
A B C H I L 6.50 days
A D E F K L 6.45 days
A D G J L 8.00 days
The case does not indicate whether it is necessary to complete A before beginning B. This could be discussed in class.
Question 2: Determine the critical path. What is the least amount of time it takes between receipt of an order and its delivery to a customer?
The critical path is A D G J L and it takes 8 days.
Question 3: Considering your answers to Questions 1 and 2, what areas of activity do you think Wood should look at first, assuming she wants to reduce order processing and delivery times? Why?
She should, of course, look at the critical path because it takes the longest and is controlling. Items G and J seem like candidates.
Question 4: Now that she is a Californian ready for the race down the information superhighway, Wood wants to be able to impress Pollack in terms of her knowledge of current technology. Recently a sales representative from a warehouse equipment company called, trying to interest her in installing a “Star Wars-Robotic” order picker for the warehouse. Controlled by lasers and powered by magnetic levitation, the device can pick orders (task H) in 15 minutes, rather than 6 hours (.75 days), the current time. How valuable would such a device be for Wood? Why?
Although the “Star Wars-Robotic” order picker offers impressive time savings, it would appear to offer limited immediate advantages in the sense that overall completion time along the critical path would be unaffected.
Question 5: Another alternative is to use faster transportation. How should Wood choose between paying more for faster transportation and paying more for other improvements? Assume that her only goal is speed.
See the answer to question 3. Wood should look at all costs along the critical path. Any improvement would have to be an item on the path; and the cost of each improvement would have to be compared with the time savings it provides.
Question 6: To offset some of the costs of speeding up the system, does the PERT chart indicate where there might be some potential savings from assigning fewer people to some tasks, thereby increasing the amount of time needed to complete these tasks? If so, which tasks are likely candidates? Why?
Wood should explore transferring workers from tasks not on the critical path, such as B, C, E, F, H, I, or K, and these workers should be transferred to tasks on the critical path. She could do this so long as the function from which the workers were transferred does not become part of a new critical path.