2023-07-122023-07-121991-12078030181Xhttps://scripta.up.edu.mx/handle/20.500.12552/3648Abstract PASION, a process- and event-oriented simulation language designed for PASCAL users, is discussed. The language has a two-level (process/event) structure and permits the use of all the PASCAL structures. It also offers the main features of object-oriented programming. PASION provides necessary facilities to handle sequences of random events, queues, and quasi-parallel processes, both discrete and continuous. Examples of simulation in PASION are presented, and implementation is discussed.It is pointed out that a major limitation of graphical user interfaces for simulation is that users such as managers and decision makers need to know too much. The author examines the weaknesses inherent in graphical user interfaces to support these users of simulation for short-term situation assessment and scenario evaluation, a style of problem-solving characteristic of military and factory command-and-control. He then presents Shoptalk, a factory command-and-control system with an interface integrating direct manipulation and natural-language processing, and demonstrates how the Shoptalk style of interaction can overcome these limitations.Resource Types::text::conference output::conference proceedings::conference paper