The CPM Procedure

Overview: CPM Procedure

The CPM procedure can be used for planning, controlling, and monitoring a project. A typical project consists of several activities that may have precedence and time constraints. Some of these activities may already be in progress; some of them may follow different work schedules. All of the activities may compete for scarce resources. PROC CPM enables you to schedule activities subject to all of these constraints.

PROC CPM enables you to define calendars and specify holidays for the different activities so that you can schedule around holidays and vacation periods. Once a project has started, you can monitor it by specifying current information or progress data that is used by PROC CPM to compute an updated schedule. You can compare the new schedule with a baseline (or target) schedule.

For projects with scarce resources, you can determine resource-constrained schedules. PROC CPM enables you to select from a wide variety of options so that you can control the scheduling process. Thus, you may select to delay project completion time or use supplementary levels of resources, or alternate resources, if they are available.

All project information is contained in SAS data sets. The input data sets used by PROC CPM are as follows:

  • The Activity data set contains all activity-related information such as activity name, precedence information, calendar used by the activity, progress information, baseline (or target schedule) information, resource requirements, time constraints, and any other information that you want to identify with each activity.

  • The Resource data set specifies resource types, resource availabilities, resource priorities, and alternate resources.

  • The Workday data set and the Calendar data set together enable you to specify any type of work pattern during a week and within each day of the week.

  • The Holiday data set enables you to associate standard holidays and vacation periods with each calendar.

The output data sets are as follows:

  • The Schedule data set contains the early, late, baseline, resource-constrained, and actual schedules and any other activity-related information that is calculated by PROC CPM.

  • The Resource Schedule data set contains the schedules for each resource used by an activity.

  • The Usage data set contains the resource usage for each of the resources used in the project.

See Chapter 5: The PM Procedure, for an interactive procedure that enables you to use a Graphical User Interface to enter and edit project information.