The brief overview of structured modeling given in Section 1 presents but a superficial glimpse of the foundations reported at length in Geoffrion [1989a], [1991], [1992a].
The remaining sections review and comment on four main categories of structured modeling research topics, including open opportunities. Section 2 covers possible improvements in SML and alternative languages for defining structured models. Section 3 deals with model integration, after distinguishing and discussing several kinds of integration. Section 4 covers extensions and adaptations for discrete event simulation. Section 5 includes three topical areas relating to implementation strategies and technologies: the leading candidates for host software upon which to erect future structured modeling environments, language-directed editors, and an implementation strategy that may improve the ease with which existing applications can be maintained and improved, and with which closely related applications might be produced quickly once the first one has been implemented.
This article covers fewer than a third of the references given in the latest annotated bibliography on structured modeling (Geoffrion [1999]). Readers will find there many additional citations, details, and important topics not discussed here.
In closing, we note that the existing body of work on structured modeling has prepared the way not only for additional basic research, applied research, and prototype development, but also for real applications. Some studies already have been done to assess the applicability of structured modeling in actual companies, including an integrated oil company in Brazil (Hamacher [1991]), a tire manufacturer in Korea (Park, Kang and Kim [1992]), the largest Korean steel company, an industrial gases company, and a telephone company. In addition, the GESCOPP project involves applications at two Chilean manufacturing firms: a candy manufacturer (Maturana and Eterovic [1995]) and the largest appliance manufacturer (Maturana, Gazmuri, and Villena [1999]).
The time is ripe for pilot applications to become the guiding force behind university-based studies.