Geographic Information Systems (GIS) is an integrated
collection of computer software and data used to view and
manage information about geographic locations, to analyze
spatial relationships and to model spatial processes. For the
analysis of the recyclables collection routing problem, the GIS
software developed by ESRI (www.esri.com), called ArcGIS
(Version 10.1) with an extension ArcGIS Network Analyst
(NA) was utilized. The NA comes with several solvers,
components that can solve tasks such as Vehicle Routing
Problem (VRP). The VRP solver is capable to account for the
limited capacity of the collection vehicle and it also allows
users to control the curb access. The geographical positions,
where the demand for recyclables collection is located, are in
the NA denoted as orders. These orders are saved in the orders
feature layer.
The algorithm in the VRP solver starts by generating an
Origin – Destination Matrix of the shortest path costs between
all orders and depot locations within the network. Using this
cost matrix, it constructs an initial solution by inserting the
orders one at a time into the most appropriate route.
The initial solution is then improved by re-sequencing the
orders on each route, as well as by moving orders from one
route to another and by exchanging orders between routes.
Heuristics used in this process is based on the tabu search
metaheuristic [5]