Implementing methods in an object oriented system for engineering

Object oriented systems are too new for a universal methodology for implementation to have evolved. Only a few implementations have been discussed in any detail in the literature. The authors discuss one of the most difficult parts of the implementation: the persistent storage of methods represented by explicit code stored with the data. They do this for an engineering environment, where methods may include processes which compute the relevant laws of physics and chemistry, carry out substantial numeric processing and process images as well as the more common processes which search through large knowledge bases, execute logical rules and analyse text objects