Hirsch, 2019; Juan, Pascual, Guimarans, &
Barrios, 2015).
The remaining of the paper is structured as fol-
lows: Section 2 presents some works on the
SSCFLP. A mathematical description of the non-
smooth SSCFLP is provided in Section 3.InSection
4, a BRILS algorithm is proposed as a solving
method for the non-smooth SSCFLP. Section 5 is
devoted to explain the computational experiments
performed. Finally, conclusions and future work are
discussed in Section 6.
2. Related work on the SSCFLP
Some seminal contributions to the FLP can be
found in Revelle, Marks, and Liebman (1970),
Guignard and Spielberg (1977), Cornuejols (1978),
and Krarup and Pruzan (1983). In the latter, the
authors mention several real-world applications
regarding the number, size, design, location, and
service patterns for “facilities” such as high schools,
hospitals, silos, slaughterhouses, warehouses, and
production plants. The survey written by Klose and
Drexl (2005) and the book edited by Eiselt and
Marianov (2011) cover many relevant works on
the FLP.
One of the most interesting FLP variants is the
aforementioned single-source capacitated FLP. Many
of solving approaches proposed for the SSCPLP are
based on obtaining good Lagrangian duals, whose
solutions improve the lower bounds provided by the
LP-relaxation. Each proposed method differs in the
constraints that are relaxed: the assignment con-
straints, the capacity constraints, or both. In add-
ition, a primal heuristic is usually included in order
to find feasible solutions. For instance, Klincewicz
and Luss (1986) relax the capacity constraints. Thus,
the uncapacitated FLP is obtained as a subproblem
and solved by employing the well-known dual
ascent algorithm. The Lagrangian relaxations are
complemented by an add heuristic, which is used to
obtain an initial feasible solution. Similarly, Pirkul
(1987) uses the Lagrangian relaxation of the capacity
constraints to develop optimal and heuristic proce-
dures for this problem. Barcel
o and Casanovas
(1984) develop several Lagrangian decompositions
and, for some of them, heuristic algorithms were
designed to solve the resulting Lagrangian subpro-
blems. Hindi and Pie
nkosz (1999) devise a heuristic
combining Lagrangian relaxation with restricted
neighbourhood search. Cortinhal and Captivo
(2003) obtain lower bounds by using a Lagrangian
relaxation, while upper bounds are achieved by
Lagrangian-based heuristics followed by search
methods and by a tabu search metaheuristic. Chen
and Ting (2008) develop a hybrid algorithm to solve
the SSCFLP. Their algorithm combines a
Lagrangian-based heuristic and an ant colony sys-
tem. The reader is referred to Galv
~
ao and Marianov
(2011) for a more comprehensive literature overview
on Lagrangian relaxation-based techniques for solv-
ing different FLP variants, including the SSCFLP.
Other heuristics have been proposed in the litera-
ture to solve the SSCFLP. Thus, Filho and Galv
~
ao
(1998) proposed a tabu search metaheuristic, while
Delmaire, D
ıaz, Fern
andez, and Ortega (1999) pro-
posed a reactive GRASP, a tabu search, and two dif-
ferent hybrid approaches that combine elements of
the GRASP and the tabu search frameworks.
R
€
onnqvist, Tragantalerngsak, and Holt (1999) pro-
pose an approach based on a repeated matching
algorithm, which essentially solves a series of match-
ing problems until certain convergence criteria are
satisfied. A very large-scale neighbourhood search
algorithm for the SSCFLP is proposed in Ahuja,
Orlin, Pallottino, Scaparra, and Scutell
a(2004).
Contreras and D
ıaz (
2007) devise a scatter search
approach to provide upper bounds for the SSCFLP.
Finally, Guastaroba and Speranza (2014) propose a
kernel search framework that is applied to
the SSCFLP.
Exact methods have also been applied to the
SSCFLP. For instance, Holmberg, R
€
onnqvist, and
Yuan (1999) devise a repeated matching algorithm,
incorporated into a Lagrangian heuristic, which is
used as a primal heuristic to solve a series of match-
ing problems until certain convergence criteria are
satisfied. Finally, a branch-and-bound method,
based on the Lagrangian heuristic, is developed and
compared to the results provided by Cplex. D
ıaz
and Fern
andez (2002) develop an exact algorithm in
which a column generation procedure for finding
upper and lower bounds is incorporated within a
branch-and-price framework. In this case computa-
tional results are reported for instances with up to
30 facilities and 90 customers. Similarly, an exact
algorithm based on a cut-and-solve framework is
introduced by Yang et al. (2012) for the SSCFLP.
They solve to optimality instances with up to 80
facilities and 400 customers.
Finally, Albareda-Sambola, Landete, Monge, and
Sainz-Pardo (2017) analyze a FLP version in which
facilities can fail with some probability. These authors
introduce soft capacity constraints on the facilities,
i.e., small violations of these constraints are allowed
for the scenario with unreliable facilities.
3. Modelling the non-smooth SSCFP
This section starts by offering a mathematical model
for the SSCFLP. Then, it extends this basic model to
the non-smooth case.
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY 1801