Modeling optimization problems in the unstructured world of spreadsheets

Electronic spreadsheets are the most common software tool managers use to analyze data and model quantitative problems. Increasingly, these software packages are being used in introductory OR/MS courses to introduce students to a variety of quantitative modeling tools. Because spreadsheets are inherently free-form, they impose no particular guidelines or structure on the way problems may be modeled. Thus, academics and practitioners accustomed to solving problems using very structured, dedicated OR/MS software packages are facing the challenge of dealing with these problems in the unstructured spreadsheet environment where there is often a variety of ways to implement and solve the same problem. This challenge is particularly acute in the case of optimization problems. Some are responding to this challenge by devising rules for implementing models that impose an artificial structure on spreadsheets, sometimes resembling the operation of dedicated OR/MS optimization packages. This paper offers a critique of this approach and provides some guidelines we believe to be more helpful in creating effective spreadsheet models for optimization problems.