Object-oriented re-engineering of manufacturing models: A case study

Current manufacturing systems have a very structured production model, expecially when high complexity and precision is required, as in semiconductor devices manufacturing. In addition, rapid changes in both production and market requirements may occur, hence great flexibility is essential. This goals, together with the capability of adding new features as well as removing some model limitations, often impose to re-engineer periodically existing models, reducing as much as possible the time-to-market of a new product. Updating a model generally also requires to improve existing applications, both re-writing software components as well as adding new features to existing components. Here the model currently used inside STMicroelectronics facilities to define production flow (the sequence of operations to be performed in order to make products) is considered. First, the model is described highlighting its limitations, then an enhanced object-oriented model is introduced, in order to provide both a better management of all entites through aggregational and constitutional hierarchies and a significant time reduction of production flow definitions through a flexible inheritance mechanism. In addition, required improvements on existing applications are considered, introducing an enhanced environment capable of supporting the enhanced model while preserving both technical and economic investments thus avoiding radical changes in existing environment.