The paper discusses the development of a computational thermal simulation engine as an object. The simulation engine utilizes Transfer Function (TF) Algorithms where all TF procedures have been implemented. The simulation is integrated with the Microsoft Windows environment and has been made to take advantage of many of this operating system’s features. In particular, the separate components of the simulation take advantage of the Windows feature to communicate - Object Linking and Embedding (OLE). Individual modules and databases exist as distinct "objects" in the memory, providing their data and functionality to each other via an object-to-object interface seen only by other programs. The OLE implementation has meant that the object developed can readily communicate with and take advantage of other applications.