The CPM Procedure

Example 2.7: Controlling the Project Calendar

This example illustrates the use of the INTERVAL=,   DAYSTART=, and DAYLENGTH= options to control the project calendar. In Example 2.1 through Example 2.5, none of these three options is specified; hence the durations are assumed to be days (INTERVAL=DAY), and work is scheduled on all seven days of the week. In Example 2.6, the specification of INTERVAL=WEEKDAY causes the schedule to skip weekends. The present example shows further ways of controlling the project calendar. For example, you may want to control the work pattern during a standard week or the start and length of the workday.

Suppose you want to schedule the project specified in Example 2.1 but you want to schedule only on weekdays from 9 a.m. to 5 p.m. To schedule the project, use the INTERVAL=WORKDAY option rather than the default INTERVAL=DAY. Then, one unit of duration is interpreted as eight hours of work. To schedule the manufacturing project to start on December 1, with an eight-hour workday and a five-day work week, you can invoke PROC CPM with the following statements. Output 2.7.1 displays the resulting schedule; the start and finish times are expressed in SAS datetime values.

  
    title 'Controlling the Project Calendar'; 
    title2 'Scheduling on Workdays'; 
    proc cpm data=widget date='1dec03'd interval=workday; 
       activity task; 
       succ     succ1 succ2 succ3; 
       duration days; 
       run; 
  
    title3 'Day Starts at 9 a.m.'; 
    proc print; 
       id task; 
       var e_: l_: t_float f_float; 
       run;
 

Output 2.7.1: Controlling the Project Calendar: INTERVAL=WORKDAY

Controlling the Project Calendar Scheduling on Workdays Day Starts at 9 a.m. task E_START E_FINISH L_START L_FINISH T_FLOAT F_FLOAT Approve Plan 01DEC03:09:00:00 05DEC03:16:59:59 01DEC03:09:00:00 05DEC03:16:59:59 0 0 Drawings 08DEC03:09:00:00 19DEC03:16:59:59 08DEC03:09:00:00 19DEC03:16:59:59 0 0 Anal. Market 08DEC03:09:00:00 12DEC03:16:59:59 19JAN04:09:00:00 23JAN04:16:59:59 30 0 Write Specs 08DEC03:09:00:00 12DEC03:16:59:59 15DEC03:09:00:00 19DEC03:16:59:59 5 5 Prototype 22DEC03:09:00:00 09JAN04:16:59:59 22DEC03:09:00:00 09JAN04:16:59:59 0 0 Mkt. Strat. 15DEC03:09:00:00 26DEC03:16:59:59 26JAN04:09:00:00 06FEB04:16:59:59 30 30 Materials 12JAN04:09:00:00 23JAN04:16:59:59 12JAN04:09:00:00 23JAN04:16:59:59 0 0 Facility 12JAN04:09:00:00 23JAN04:16:59:59 12JAN04:09:00:00 23JAN04:16:59:59 0 0 Init. Prod. 26JAN04:09:00:00 06FEB04:16:59:59 26JAN04:09:00:00 06FEB04:16:59:59 0 0 Evaluate 09FEB04:09:00:00 20FEB04:16:59:59 16FEB04:09:00:00 27FEB04:16:59:59 5 5 Test Market 09FEB04:09:00:00 27FEB04:16:59:59 09FEB04:09:00:00 27FEB04:16:59:59 0 0 Changes 01MAR04:09:00:00 05MAR04:16:59:59 01MAR04:09:00:00 05MAR04:16:59:59 0 0 Production 08MAR04:09:00:00 08MAR04:09:00:00 08MAR04:09:00:00 08MAR04:09:00:00 0 0 Marketing 09FEB04:09:00:00 09FEB04:09:00:00 08MAR04:09:00:00 08MAR04:09:00:00 20 20

If you want to change the length of the workday, use the DAYLENGTH= option in the PROC CPM statement. For example, if you want an eight-and-a-half hour workday instead of the default eight-hour workday, you should include DAYLENGTH='08:30'T in the PROC CPM statement. In addition, you might also want to change the start of the workday. The workday starts at 9 a.m., by default. To change the default, use the DAYSTART= option. The following program schedules the project to start at 7 a.m. on December 1. The project is scheduled on eight-and-a-half hour workdays each starting at 7 a.m. Output 2.7.2 displays the resulting schedule produced by PROC CPM.

  
    proc cpm data=widget date='1dec03'd interval=workday 
             daylength='08:30't daystart='07:00't; 
       activity task; 
       succ     succ1 succ2 succ3; 
       duration days; 
       run;
 

  
    title3 'Day Starts at 7 a.m. and is 8.5 Hours Long'; 
    proc print; 
       id task; 
       var e_: l_: t_float f_float; 
       run;
 

Output 2.7.2: Controlling the Project Calendar: DAYSTART and DAYLENGTH

Controlling the Project Calendar Scheduling on Workdays Day Starts at 7 a.m. and is 8.5 Hours Long task E_START E_FINISH L_START L_FINISH T_FLOAT F_FLOAT Approve Plan 01DEC03:07:00:00 05DEC03:15:29:59 01DEC03:07:00:00 05DEC03:15:29:59 0 0 Drawings 08DEC03:07:00:00 19DEC03:15:29:59 08DEC03:07:00:00 19DEC03:15:29:59 0 0 Anal. Market 08DEC03:07:00:00 12DEC03:15:29:59 19JAN04:07:00:00 23JAN04:15:29:59 30 0 Write Specs 08DEC03:07:00:00 12DEC03:15:29:59 15DEC03:07:00:00 19DEC03:15:29:59 5 5 Prototype 22DEC03:07:00:00 09JAN04:15:29:59 22DEC03:07:00:00 09JAN04:15:29:59 0 0 Mkt. Strat. 15DEC03:07:00:00 26DEC03:15:29:59 26JAN04:07:00:00 06FEB04:15:29:59 30 30 Materials 12JAN04:07:00:00 23JAN04:15:29:59 12JAN04:07:00:00 23JAN04:15:29:59 0 0 Facility 12JAN04:07:00:00 23JAN04:15:29:59 12JAN04:07:00:00 23JAN04:15:29:59 0 0 Init. Prod. 26JAN04:07:00:00 06FEB04:15:29:59 26JAN04:07:00:00 06FEB04:15:29:59 0 0 Evaluate 09FEB04:07:00:00 20FEB04:15:29:59 16FEB04:07:00:00 27FEB04:15:29:59 5 5 Test Market 09FEB04:07:00:00 27FEB04:15:29:59 09FEB04:07:00:00 27FEB04:15:29:59 0 0 Changes 01MAR04:07:00:00 05MAR04:15:29:59 01MAR04:07:00:00 05MAR04:15:29:59 0 0 Production 08MAR04:07:00:00 08MAR04:07:00:00 08MAR04:07:00:00 08MAR04:07:00:00 0 0 Marketing 09FEB04:07:00:00 09FEB04:07:00:00 08MAR04:07:00:00 08MAR04:07:00:00 20 20

An alternate way of specifying the start of each working day is to set the INTERVAL= option to DTWRKDAY and specify a SAS datetime value for the project start date. Using INTERVAL=DTWRKDAY tells CPM that the DATE= option is a SAS datetime value and that the time given is the start of the workday. For the present example, you could have used DATE='1dec03:07:00'dt in conjunction with the specification INTERVAL=DTWRKDAY and DAYLENGTH='08:30't.