An introduction to the ASCEND modeling system: Its language and interactive environment

Recently there has been a growing realization among researchers and practitioners that current technologies do not adequately support mathematical modeling ‘in the large’. In this paper the authors discuss a technology called ASCEND (Advanced System for Computations in Engineering Design), which addresses this issue. They describe two aspects of the technology: a modeling language and an interactive model-building environment. The ASCEND language is structured, declarative, and strongly typed, and incorproates object-oriented extensions. The interactive environment is based on the notion of a concurrent set of tools that reflect the various phases of ASCEND modeling. These tools do not enforce a strict sequence of operations, but rather have been designed to support the flexible access implied by declaratively specified models. The authors claim that ASCEND offers solutions to several of the issues raised by Arthur Geoffrion in his article, ‘Computer-based modeling environments’, and use categories introduced by him to frame this discussion.