The one and only

1. Structured Modeling, draft research monograph, Western Management Science Institute, UCLA, 197 pages, 1/85. Revised 1/6/86. Requests are no longer being filled.

This originally was intended to be the heart of a book on SM. The topic kept expanding and developing, however, so the monograph was cannibalized and extended as a series of working papers. Some day the pieces may be put back together as a monograph.

2. "An Introduction to Structured Modeling," Management Science, 33:5 (May 1987), pp. 547-588. WMSI Reprint 219. Formerly WMSI Working Paper 338, 6/86 (revised 12/86, 2/87, 5/87, 8/87, 3/88).

This introductory exposition serves as the basic reference for all other papers on SM.

3. "Modeling Approaches and Systems Related to Structured Modeling," WMSI Working Paper 339, 27 pages, drafted 7/86; revised and released 2/87. Needs revision.

This companion paper to the previous one discusses related modeling approaches and systems by other authors. It was intended to elicit comments from the authors referenced.

4. "Integrated Modeling Systems," Computer Science in Economics and Management, 2:1 (1989), pp. 3-15. WMSI Reprint 238. Formerly WMSI Working Paper 343, 11/86 (revised 8/87, 3/88).

This paper discusses the general concept of integrated modeling systems in some detail and then considers how SM supports the different kinds of integration that are identified. Extensive use is made of the notion of a four-level model abstraction hierarchy: model instance, model class, modeling paradigm, and modeling tradition.

5. "The Formal Aspects of Structured Modeling," Operations Research, 37:1 (January-February, 1989), pp. 30-51. WMSI Reprint 234. Formerly WMSI Working Paper 346, 5/87 (revised 9/88, 1/89).

This companion to my 1987 Management Science article motivates and formally presents the definitions of all core concepts of SM, and the definitions of associated concepts and constructs. It also presents pertinent basic theory. A tightly integrated running example illustrates all of the main ideas. It stops short of presenting a language for representing structured models, but provides the foundation for all such languages.

6. "SML: A Model Definition Language for Structured Modeling," WMSI Working Paper 360, 129 pages, 5/88. Revised 11/89, 8/90 (now 137 pages). Not intended for publication.

This paper presents a complete language, SML, built on the core concepts of SM as applied to model definition, both for specific model instances and for classes of models. It also establishes rigorously the relationship between SML and the core concepts of SM. The FW/SM prototype implements SML. This paper is a reference work and not a tutorial; for that, see item 11 below.

7. "Computer-Based Modeling Environments," European Journal of Operational Research, 41:1 (July 1989), pp. 33-43. WMSI Reprint 237. Formerly WMSI Working Paper 363, 12/88.

This paper, a written version of two plenary speeches, says very little about SM but a lot about my views of what future modeling environments should be like. In particular, it discusses five desirable characteristics and three of the main design challenges that need to be surmounted in order to achieve this vision.

8. "Reusing Structured Models via Model Integration," Proceedings of the Twenty-Second Annual Hawaii International Conference on System Sciences, IEEE Computer Society Press, Los Alamitos, CA, pp. 601-611, held in Kailua-Kona, January 3-6, 1989. WMSI Reprint 233. Formerly WMSI Working Paper 362, 8/88 (derived from an earlier Informal Note), the appendices of which contain 3 detailed examples not in the published version. Minor revision (4/92), complete with appendices, reprinted in R. Blanning and D. King (eds.), Current Research in Decision Support Technology, IEEE Computer Society Press, pp. 25-55, July 1992.

This paper begins with a review of reusability and modularity ideas from the software engineering literature, most of which are applicable to the modeling context. Many features of SM support reusability and modularity, and these are noted. The main focus of the paper, however, is on achieving reusability and modularity via the integration of two or more models. A 5-step procedure for SML schema integration is proposed for this purpose. Detailed examples illustrate this procedure, and the pros and cons of SM for reuse are discussed at some length.

Some of this paper's examples are reused and discussed from an alternative viewpoint in R. Krishnan, P. Piela, and A. Westerberg, "Reusing Mathematical Models in ASCEND," in C. Holsapple and A. Whinston (eds.), Recent Developments in Decision Support Systems, Springer-Verlag, Berlin, 1993. One of the examples is the basis for the appendix of A. Andronico, L. Cossa, M. Gagliardi and C. Spera, "An Object Oriented Approach to a Model Management System: Characteristics and Examples" (see Part IIB of this Bibliography). Most of the examples are discussed in detail in M. Gagliardi and C. Spera, "Toward a Formal Theory of Model Integration" (see Part IIB of this Bibliography).

9. "Indexing in Modeling Languages for Mathematical Programming," Management Science, 38:3 (March 1992), pp. 325-344. An earlier version appeared as "A Taxonomy of Indexing Structures for Mathematical Programming Modeling Languages," Proceedings of the Twenty-Third Annual Hawaii International Conference on System Sciences, Vol. III, IEEE Computer Society Press, Los Alamitos, CA, pp. 463-473, held in Kailua-Kona, January 2-5, 1990; WMSI Reprint 241. Additional details appear in the appendices of WMSI Working Paper 371, 180 pages, 11/89 (revised 10/90 and 7/91).

All but the most rudimentary algebraic modeling languages for mathematical programming permit constants, variables, expressions, and constraints to be indexed. Because indexing plays a critical role in the design of translators from modeling languages into optimizer-ready data files, this paper takes a close look at exactly what one means by "indexing", and makes a comparative analysis of modeling languages from this point of view.

A taxonomy is given of the most commonly used kinds of indexing structures, namely those based on sets and relations, together with 25 detailed examples illustrating all categories of this taxonomy. We argue for the presence