Richard G. Born

WebGPSS: the first two hours of simulation education

In this paper we present seven short lessons used for introducing management science students to discrete event simulation. It has been used both as the only element of such simulation in courses that devote only two classroom hours to this topic and as the introduction in courses that are devoted almost completely to simulation.

GPSS 50 years old, but still young

In 2011, GPSS, the General Purpose Simulation System, celebrates its 50th anniversary. At the 2001 Winter Simulation Conference there were two papers dealing with the 40th anniversary of GPSS. With these papers available on the Web, this paper will concentrate on the developments of GPSS after 2001. There are still three systems with the GPSS name that are sold, supported and improved: GPSS/H, GPSS World and the educational aGPSS systems family. There has also been a substantial development of the successor of GPSS/H, SLX. Finally, Proof Animation, which is closely connected to some of the GPSS systems, has been substantially improved during the last decade.

Teaming discrete-event simulation and geographic information systems to solve a temporal/spatial business problem

Although discrete-event simulation has pedagogically been rooted in computer science, and the practicality of geographic information systems in geography, the combined use of both in the business world allows solving some very challenging temporal/spatial (time and space dependent) business problems. The discrete-event simulation language WebGPSS, an ideal simulation environment for the business person, is teamed with Microsoft MapPoint, a GIS (geographic information system) designed to bring powerful mapping and analysis techniques to corporate office desktops. The result is the ability to solve innovative business strategy problems before implementing them in the real world. This paper focuses on one such problem by using WebGPSS to drive a simulation that provides geographic data for display by MapPoint, and ultimately map animations showing spatial and temporal business changes.

Theoretical performance-based cost-effectiveness of multicomputers

The CPU cycles that are stolen to relay messages can significantly affect the performance of a multicomputer system. This degradation in performance in turn affects the overall cost-effectiveness of such a system. This paper compares the cost-effectiveness of four multicomputer architectures that have received a great deal of recent attention: the bidirectional straight line, the unidirectional ring, the square mesh, and the binary hypercube. Cost-effectiveness is measured by finding the ratio of the total dollar cost of a multicomputer, based upon the total cost of processors and communication links, to the total potential utilization of the processors making up the system, where the potential utilization is the fraction of time a processor has to do useful processing after subtracting time spent handling messages. The smaller the value of this ratio, the greater the cost-effectiveness of the system.

Teaching simulation to ten thousand students: American-European cooperation and perspectives

This paper deals with the cooperation between three European and American simulation teachers, who together have taught simulation to over ten thousand students in five countries. They have, based on student feedback, developed an educational version of GPSS, the General Purpose Simulation System. This simplified system, aGPSS, has proved to be very easy to learn and also to use, for example, in student projects. The three teachers have also together written simulation textbooks in English and German.

From emergency departments to cottage cheese to fire departments: learning simulation experimentation through WebGPSS

An important component of any simulation course is the discussion of experimental design. WebGPSS has been used by the author for two years to discuss experimentation in an introductory course in discrete-event simulation. This paper discusses how to set up simulation experiments using WebGPSS by presenting three business problems whose solutions require careful attention to experimental design. The first problem looks at staffing an emergency department of a hospital with physicians. The second problem involves the optimal method for stocking a perishable food product such as cottage cheese on a supermarket shelf, showing that under realistic conditions, spoilage can be minimized by placing newer containers in the front. The third problem involves analysis of a proposal for two neighboring communities currently operating completely separate fire departments to integrate their two systems in a way that could reduce the amount of time that fires are unattended.

Packet-switching network performance under real-time voice-call loading

Abstract The performance characteristics of packet-switching networks carrying real-time voice calls are of major interest in network design. This paper describes a real-time voice-call model in which voice packets are transmitted over virtual circuits on a variety of simulated packet-switching networks. These networks range from current mid-range packet-switching networks to those using frame relay with T1 links and cell relay with fiber-optic links. Performance characteristics under varying voice-call loads are presented. These characteristics include node utilization statistics, circuit utilization statistics, nodal buffer use, buffer use by circuits, packet queue time, packet-switch wait time, mean end-to-end packet delay, and voice delays.