We define a high volume factory to be a connected network of workstati
ons, at which assigned workers process work-in-progress that flows at
high rates through the workstations. A high rate usually implies that
each worker processes many pieces per hour, enough so that work can be
described as a deterministic hourly flow rate rather than, say, a sto
chastic number of discrete entities. Examples include mail processing
and sorting, check processing, telephoned order processing, and inspec
ting and packaging of certain foods. Exogenous work may enter the fact
ory at any workstation according to any time-of-day profile. Work-in-p
rogress flows through the factory in discrete time according to Markov
ian routings. Workers, who in general are cross-trained, may work part
time or full time shifts, may start work only at designated shift sta
rting times, and may change job assignments at mid shift. In order to
smooth the flow of work-in-progress through the service factory, work-
in-progress may be temporarily inventoried (in buffers) at work statio
ns. The objective is to schedule the workers (and correspondingly, the
workflow) in a manner that minimizes labor costs subject to a variety
of service-level, contractual and physical constraints. Motivated in
part by analysis techniques of discrete time linear time-invariant (LT
I) systems, an object-oriented linear programming (OOLP) model is deve
loped. Using exogenous input work profiles typical of large U.S. mail
processing facilities, illustrative computational results are included
.