Uses of the SIMULA process concept

The class concept of the SIMULA programming language is well known as the father of the concept of abstract data types. A SIMULA class can however also act as a process. This paper illustrates by some examples for existing programs how the process aspect of the class concept can be used to structure programs in neat ways. All the examples are taken from real production programs in heavy usage today, but the examples have been simplified in this paper to illustrate the main ideas.