Publication Details: UM-CS-2014-009

Discrete-Event Simulation and Integer Linear Programming for Constraint-Aware Resource Scheduling

Publication Type:Technical Report
Author(s):S. Shin, H. Balasubramanian, Y. Brun, P. L. Henneman, L. J. Osterweil
Abstract:This paper presents a method for scheduling resources in complex
systems that integrate humans with diverse hardware and software
components, and to study the impact of resource schedules on system
characteristics. The method uses discrete-event simulation and integer
linear programming, and relies on detailed models of the system's
processes, specifications of the capabilities of the system's
resources, and constraints on the operations of the system and its
resources. As a case study, we examined processes involved in the
operation of a hospital emergency department, studying the impact
staffing policies have on such key quality measures as patient length
of stay, numbers of handoffs, staff utilization levels, and cost. Our
results suggest that physician and nurse utilization levels for
clinical tasks of 70% result in a good balance between length of stay
and cost. Allowing shift lengths to vary and shifts to overlap
increases scheduling flexibility. Clinical experts provided face
validation of our results. Our approach improves on the state of the
art by enabling using detailed resource and constraint specifications
effectively to support analysis and decision-making about complex
processes in domains that currently rely largely on trial and error
and other ad hoc methods.