A manpower levelling/project planning program

This paper presents the design of a program for monthly development of detailed daily schedules of manpower assignments. Scheduling is normally performed by a heuristic project scheduling routine. However, facilities for user intervention and overrides are incorporated. While actual limits are fixed by the availability of offline storage, the scheduler is designed to handle up to 40,000 activities, 200 resources and any number of different project networks. Through an extensive use of program overlays and linked data records on random access storage, core requirements are less than 17K 24 bit words for a compiled program. A multiple pass scheduling algorithm is used. Activities are partitioned into three sets depending upon their externally specified priority. Activities in the first set are scheduled first; the availability of resources is adjusted to reflect this schedule, the second set of activities is scheduled, etc. When properly used, this feature compensates for the common tendency of one-pass heuristic algorithms to schedule low priority, high slack activities as soon as excess resources are available, even if this ties up resources that in a few days are required to schedule more critical activities. This program is written in COBOL and is currently implemented on a Honeywell (GE) 465 computer as a subsystem of a larger management control system.