A regular service event is defined as an event that is handled
by the HHD unit; an irregular event is handled by another unit in the supply network. As shown in Table II, the number of dialyses per patient, and the percentage of them performed at home; the number of events and the percentage of themfirst case could be neatly modeled as an ordered flow of routines, the second case appeared as a nonroutine process displaying varying strings of events