Just modeling through: a rough guide to modeling

Just Modeling Through: A Rough Guide to Modeling
Michael Pidd
Department of Management Science The Management School Lancaster University Lancaster LA1 4YX United Kingdom

Skill in modeling is one of the keys to success in OR/MS practice. This has been recognized for many years, but we often give it only lip service. Models are used in many ways in OR/MS practice. A few simple principles of modeling may be useful. The six principles discussed here cover simplicity versus complexity; model development as a gradual, almost piecemeal process; dividing larger models into smaller components; using analogies; proper uses of data; and finally the way in which the modeling process can seem chaotic. Others may wish to comment on these principles and add their own. hen I am fortunate enough to visit a new country, I usually try to buy one of the Rough Guides, since the prejudices of the writers seem fairly close to my own. The guides point out the good (and bad) in the place to be visited, and they attempt the impossible by trying to give a flavor of the country in a few pages. I have been active in OR/MS both as an academic and as a practitioner since the early 1970s. In my experience, the real technical heart of OR/MS can be summaCopyright 1999, Institute for Operations Research and the Management Sciences 0092-2102/99/2902/0118/$5.00 This paper was refereed.

W

rized in the one word, modeling. In this paper, I will attempt to provide a rough guide to modeling, with principles that I and others have found useful and that seem to resonate with students and practitioners. Others have written at length on the useful principles of modeling. Morris [1967] outlined some hypotheses about modeling that he had found useful and that illustrate the difference between modeling as an intuitive process and the forPROFESSIONAL—OR/MS EDUCATION PHILOSOPHY OF MODELING

INTERFACES 29: 2 March–April 1999 (pp. 118–132)

A ROUGH GUIDE mal study of existing models. Little [1970]