Suppose, after doing the analysis in Example 15.2, the project manager sees a problem with the current setup. Activity C, selecting the server, requires five systems people, and activity D, selecting the software, requires seven systems people. The problem is that these two activities are scheduled concurrently, even though it turns out that four of the five systems people for activity C and four of the seven systems people for activity D are the same people. Assuming that a given person can work on only one activity at a time, some changes need to be made.
a. One possible change is to assign two of the four people in common to activity C and the other two to activity D. Now three people will be assigned to activity C and five people will be assigned to activity D. Unfortunately, with fewer people assigned, the durations of these activities will increase from 6 days to 9 days for activity C and from 12 days to 14 days for activity D. How much will these changes delay the project?
b. Another possible change is to make activity D a successor to activity C, so that the four common people can continue to be assigned to both activities. How should the AON diagram for the project be redrawn? How much will this change delay the project?
c. What other changes might you suggest?
EXAMPLE 15.2 MONITORING RESOURCES FOR THE LAN PROJECT
Recall from Example 15.1 that an insurance company is creating a LAN for one of its large offices. In that example, we provided activity durations for the 15 activities in the project, and we showed that with these durations, the project can be completed in 62 days. We now make some assumptions about the money and people resources that are implicit in these activity durations. First, we assume that the various activities require different technical expertise, which comes from five groups of people: engineering, systems, purchasing, installers, and training. To achieve the durations used in Example 15.1, we assume the numbers of people required per day for the various activities are those shown in Table 15.3. For example, to perform the needs analysis in 10 days, six engineers are required per day. Note that connecting the network is the only activity that requires two
different types of people: three systems people and five installers for each of the three days this activity takes to complete. Also, note that the last activity, getting management acceptance, doesn’t show any people requirements. In reality, this activity is probably the responsibility of the project manager, who is busy throughout the entire project. (Almost all projects have a project manager.) In addition to these people, the various activities require money. It certainly costs money to pay the people, and there are probably other costs as well. We assume the costs per day for the various activities are those shown in Table 15.4. The company wants to see how its people and money are used over time. Also, because some of the activities have some slack, the company wants to see how the resource usages are affected by adjusting the starting times of the noncritical activities.
Objective To create time series charts of the money and people usages, and to see how these are affected by the starting times of the noncritical activities.
WHERE DO THE NUMBERS COME FROM?
The numbers of people required per day, shown in Table 15.3, are probably based on technical considerations of the activities. In fact, these numbers are probably chosen first, and activity durations are then based on them. For example, the company might estimate that it takes eight installers to wire the offices properly, and if eight installers are used per day, the wiring can then be completed in 12 days. The costs in Table 15.4 are based on the wage rates of the various types of people, plus any other expenses required to perform the activities.