OR/SM: A prototype integrated modeling environment based on structured modeling. This article describes the design and implementation of OR/SM, a computerized modeling environment based on structured modeling. The uniqueness of OR/SM is in the following: (1) the use of ORACLE tools and database as the delivery platform; (2) automatic and interactive links to SAS, a powerful and widely used commercial statistical analysis software system and optimization solver; and (3) an interactive link to QS (quantitative systems) – a commercial software package for solving a wide range of operations management models. Some other key features are: (1) automatic generation of relational database tables for model data; (2) interactive checking of model syntax and semantics; and (3) automatic generation of several reference documents. Examples from blending, inventory control, and marketing mix management are used to illustrate the capabilities of OR/SM.