The use of ontologies in discrete-event simulation

data types, objects, classes and inheritance. Many consider SIMULA 67 to be the first object oriented programming language. SIMSCRIPT (Markowitz, Hausner and Karr 1962) is an SPL that, in its original form, conformed to the event scheduling world view. The original version of SIMSCRIPT (often referred to as SIMSCRIPT I) allows the modeler to describe a simulation model in terms of entities, attributes, sets and events. The static portion of a SIMSCRIPT I model is constructed using a definition form upon which entities, their attributes and the sets with which they are associated are specified; and an initialization form upon which the initial state of the model is specified. The dynamic portion of a model is constructed using the SIMSCRIPT language to describe events, and the format of simulation output is specified using a report generator. SIMSCRIPT I was developed with the intention that it would be used by those who were not experts in computing, and its primary purpose was to reduce the time required to implement large models. SIMSCRIPT II (Kiviat, Villanueva and Markowitz 1968) dropped the idea of using forms and used other means to describe the static portion of a model. The SIMSCRIPT language has gone through several iterations of development since the introduction of SIMSCRIPT I. A proprietary version of SIMSCRIPT I, named SIMSCRIPT I.5 was developed by CACI (Karr 1966) in the mid-1960s and SIMSCRIPT II was introduced a short time later. SIMSCRIPT II still conformed to the event-scheduling world view using the event, attribute and set concepts found in SIMSCRIPT I, but it differed from SIMSCRIPT I (and SIMSCRIPT I.5) in that it read more like a natural language. SIMSCRIPT II was intended to be self-documenting and it was hoped that it could be used to improve the dialog between model developers and those who actually used the simulations. In the mid-1970s SIMSCRIPT was