This is a problem of building five houses in different locations; the masonry, roofing, painting, and so forth. Some tasks must necessarily take place before others and these requirements are expressed through precedencesubject to.
There are two workers and each task requires a specific worker. The worker has a calendar of days off that must be taken into account. The objective is to minimize the overall completion date.
To access this example, go to: examples/opl/sched_calendar.
See also the Adding Calendars to the House Building Problem section of the Language User's Manual, where this problem is discussed in more detail.
PS : this example come from ILOG IBM, they introduce a intensity notion