Classifiction of location models

There are several good reasons to introduce classification schemes for optimization models. For instance, the ability to make concise problem statements, as opposed to verbal, often ambiguous, descriptions. Or the possibility of simple data encoding and information retrieval in bibliographical information systems and software libraries. Therefore, in some branches of optimization, such as scheduling and queuing theory, classification is a widely used tool. The aim of this paper is to propose a 5-position classification that can be used to describe all location models. We provide a list of currently available symbols and indicate their usefulness in a (necessarily non-comprehensive) list of ‘classical’ location models. The classification scheme has been in use since 1992 and has proven to be helpful in research, software development, classroom teaching, and for overview articles.