Most GPSS versions, e.g. those of IBM and Wolverine Software, have been characterized by gradually increasing complexity. This can be exemplified by an increase from the 25 block types of the first GPSS of 1961 to the 68 block types of GPSS/H (3) of 1995. A quite different development has taken place with micro-GPSS/WebGPSS, focussed on ease-of-learning. The starting point was Schriber's Red book from 1974, based on GPSS 360 with 44 block types, out of which 31 were discussed in the book and 28 were used in the 27 case studies of this book. Based on feed-back from over 5000 students, we were in the 80's able to bring this down to 22 block types, with which we could rewrite not only the 27 case studies of the Red book, but also 99 percent of the programs in other GPSS text books, all with roughly the same amount of code. In the 90's the focus of development has been on a GUI for constructing the GPSS programs and on putting the micro-GPSS system on the Web, in the form of WebGPSS (at www.webgpss.com). Initially, WebGPSS had only 16 block types, leaving out some important functionality of micro-GPSS. We have recently, by adding two block types and allowing four others to be handled by already existing blocks, been able to give WebGPSS the full functionality of micro-GPSS. After also adding automatic animation capabilities, we believe that WebGPSS will be a very powerful tool for getting students into simulation.
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.