Specifying Resource Availability

It's likely that many of your resources will work full-time on your project. But suppose you have two part-timers: one is available half-time, and the other is available three out of the five working days.

You can specify this kind of resource availability by setting the resource's maximum units, also referred to as resource units. The full-time resources are each available at 100 percent maximum units. The half-time resource is available at 50 percent maximum units. The other part-timer is available at 60 percent maximum units. When you assign resources to tasks, those tasks are scheduled according to that resource's availability.

But 50 percent of what, you might ask? The maximum units is the percentage of time shown as available in the resource's working time calendar. If a resource calendar shows working time of Monday through Friday, 8:00 A.M. until 5:00 P.M., with an hour off for lunch, then 100% maximum units means a 40-hour workweek. 50% maximum units means a 20-hour workweek. Likewise, if a resource calendar shows working time of Monday through Friday, 9:00 A.M. until 1:00 P.M., then 100% maximum units means a 20-hour workweek. 50% maximum units for this resource would be a 10-hour workweek.

Here's another scenario: suppose that you have three engineers, two architects, and four drafters, all working a full-time schedule. Instead of naming them individually, you decide you want to name your resources by their functions and consolidate them into a single resource representing multiple individuals. You can do that with maximum units as well. The three engineers together are available at 300 percent, the two architects at 200 percent, and the four drafters at 400 percent.

If you have three full-time drafters and one half-time drafter, your Drafters resource is available at 350 percent maximum units.

To enter maximum units, simply type the percentage in the Max. Units field in the Resource Sheet (see Figure 6-8).

— Maximum resource units

Figure 6-8. You can enter maximum units when you enter resource names, or come back to it later. The default for the Max. Units field is 100%.

Figure 6-8. You can enter maximum units when you enter resource names, or come back to it later. The default for the Max. Units field is 100%.

Now, suppose your staffing plan specifies that you'll start the project life cycle needing four drafters. After three months, you'll need only three drafters. Two months later, you'll need only one. To specify variable resource quantity or availability over time, follow these steps:

1 In the Resource Sheet, click the resource whose maximum units you want to adjust.

2 On the Standard toolbar, click Resource Information. Or simply double-click the resource name.

The Resource Information dialog box appears. Make sure the General tab is displayed (see Figure 6-9).

Figure 6-9. Use the Resource Information dialog box to enter detailed information about an individual or consolidated resource.

Figure 6-9. Use the Resource Information dialog box to enter detailed information about an individual or consolidated resource.

Under Resource Availability, enter the first date range for the resource's units specification. That is, enter the beginning date, the ending date, and the maximum units that will be available during those dates. For example, in the first row enter 1/5/04 under Available From; enter 3/26/04 under Available To; enter 400% under Units.

In the second row, enter the second date range for the resource's units specification. For example, enter 3/29/04 under Available From; enter 6/25/04 under Available To; enter 300% under Units.

Continue in this manner until your entire resource availability specification is set. For example, enter 6/28/04 under Available From; enter 8/27/04 under Available To; enter 100% under Units (see Figure 6-10).