The investigation of a class of capacitated arc routing problems : the collection of garbage in developing countries
This thesis is concerned with the collection of garbage in developing countries
where the weather is hot. This problem is modelled as a Capacitated Arc Routing
Problem (CARP) with multiple trips while taking into consideration the cost
and the effect of the smell of the garbage on the environment. Smell is used as a
shorthand for health hazard. The first part of the study introduces managing solid
waste in developing countries with much reference to Ghana, and provides a review
of the literature with respect to Capacitated Arc Routing and its related problems.
The second part provides a constructive heuristic, which takes into account
the environmental aspect as well as the cost to solve the routing aspect of garbage
collection. This is based on a look-ahead strategy, which is enhanced by two additional
procedures. This idea is extended to solve the multi-vehicle CARP. Two
constructive heuristics, namely bin-packing and multi-vehicle-based approaches are
designed to solve the problem with the intention of minimising overtime. The third
part of the thesis develops a Variable Neighbourhood Search metaheuristic as a post
optimiser to improve further the solutions obtained by the use of the look-ahead
strategy. Computational testing is carried out on the test problems used in the
literature. Encouraging results for the CARP were generated under two scenarios,
namely with and without the presence of the environment. The fourth part of the
thesis deals with a real life garbage collection problem, which exists in one portion
of the Kumasi Metropolitan Assembly in Ghana. Interesting results are found when
compared to the presently used implementation. The input is gathered using GPS,
by hand and via simple mathematical expressions based on the feedback of the users.
Some suggestions for future research are emphasised.