  Mobile medical units (MMUs) are customized vehicles fitted with medical
equipment that are used to provide primary care in rural environments. As MMUs
can be easily relocated, they enable a demand-oriented, flexible, and local
provision of health services. In this paper, we investigate the strategic
planning of an MMU service by deciding where MMU operation sites should be set
up and how often these should be serviced. To that end, we study the strategic
planning problem for MMUs (SPMMU) $-$ a capacitated set covering problem that
includes existing practices and two types of patient demands: (i) steerable
demands representing patients who seek health services through a centralized
appointment system and can be steered to any treatment facility within a given
consideration set and (ii) unsteerable demands representing walk-in patients
who always visit the closest available treatment facility. We propose an
integer linear program for the SPMMU that can be solved via Benders
decomposition and constraint generation. Starting from this formulation, we
focus on the uncertain version of the problem in which steerable and
unsteerable demands are modeled as random variables that may vary within a
given interval. Using methods from robust optimization and duality theory, we
devise exact constraint generation methods to solve the robust counterparts for
interval and budgeted uncertainty sets. All our results transfer to the
session-specific SPMMU and we evaluate our models in a computational study
based on a set of instances generated from a rural primary care system in
Germany.
