Abstract. The importance of tuning a search algorithm for the specific features of the target search space has been known for quite some time. However, when dealing with multiobjective problems, there are several twists on the conventional notions of fitness landscapes. Multiobjective optimization problems provide additional difficulties for those seeking to study the properties of the search space. However, the requirement of finding multiple candidate solutions to the problem also introduces new potentially exploitable structure. This paper provides a somewhat high-level overview of multiobjective search space and fitness landscape analysis and examines the impact of these features on the multiobjective generalized assignment problem.
Why Landscape AnalysisOne of the foremost questions facing designers of metaheuristic algorithms for any sort of problem is how the structure of the objective function will affect the behavior of the search algorithm. It is known, and quite intuitive, that incorporating problem-specific knowledge into a search algorithm can often substantially increase the performance of the algorithm. However, given multiple conflicting options for building such algorithms, comparatively little is known concerning the right choices, or even the right information necessary to make good decisions.This work examines a set of tools developed to help gain insights into how various algorithms navigate complex multiobjective search spaces. Many of these tools have previously been described in relation to conventional optimization problems. In such cases, the implications of extending the tools into the multiobjective realm are carefully examined. In this work, we propose some methods by which such relevant information may be obtained and exploited, and we apply these methods to a pair of classes of assignment problems exhibiting markedly different types of structure.
Fitness Landscape AnalysisAs more and more researchers have turned their attention to modeling search algorithm performance, a number of techniques have been proposed to classify fitness landscapes, generally corresponding to fundamental properties of a given search