Simulation News Europe (SNE) features a series on comparisons of simulation software. Based on simple, easily comprehensible models special features of modelling and experimentation within simulation languages, also with respect to an application area, are compared.

Features are, for instance: modelling technique, event handling, numerical integration, steady-state calculation, distribution fitting, parameter sweep, output analysis, animation, complex logic strategies, submodels, macros, statistical features etc.

Ten comparisons have been defined in Simulation News Europe, the series will be continued. Furthermore, a special comparison of parallel simulation techniques has been defined.

Comparison 1 (Lithium-Cluster Dynamics under Electron Bombardment, November 1990)
deals with a stiff system of 3rd order. This comparison tests features for integration of stiff systems, for parameter variation, and for steady state calculation. A preliminary summary can be found in SNE 6, November 1992.
Comparison 2 (Flexible Assembly System, March 1991, comments July 1991)
for discrete simulation languages compares features for submodel structures, control strategies, and optimization of process parameters. A preliminary evaluation can be found in SNE 4.
Comparison 3 (Analysis of a Generalized Class-E Amplifier, July 1991)
focusses on simulation of electronic circuits and requires features for table functions, eigenvalue analysis, and complex experiments.
Comparison 4 (Dining Philosophers I, November 1991)
is a more general task involving not only simulation but also different modelling techniques like Petri nets.
Comparison 5 (Two State Model, March 1992, revised July 1992)
primarily addresses simulation tools with very high accurracy. It checks integration and state event handling with high accurracy.
Comparison 6 (Emergency Department - Follow-up Treatment, November 1992)
addresses discrete simulation languages and tests features for modelling, concepts of availability, and complex control strategies.
Comparison 7 (Constrained Pendulum, March 1993)
for continuous simulation languages, checks features for model comparison, state events, and boundary value problems.
Comparison CP1 (Parallel Comparison, March 1994)
This type of comparison diffenrent to the others deals with the benefits of distributed and parallel computation for simulation tasks. Three test examples have been chosen to investigate the types of parallelisation techniques best suited to particular types of simulation tasks.
Comparison 8 (Canal-and-Lock System, March 1996)
for discrete simulators checks features for modeling complex logic, which has to be verified by deterministic datasets. Also variance reduction capabilities are checked.
Comparison 9 (Fuzzy Control of a Two Tank System, July 1996)
asks for modules for fuzzy control or how such modules can be implemented efficiently.
Comparison 10 (Dining Philosophers II, November 1996)
reviews discrete simulators with respect to simultaneous (concurrent) access to resources and with respect to deadlocks.
Comparison 11 (SCARA Robot, March 1998)
is the 6th comparison of continuous type and deals with the handling of implicit systems.
Comparison 12 (Collision Processes in Rows of Spheres, November 1999)
This comparison deals with a model of the mechanics. The features to be compared represent a large number of events, the numerical accuracy, the iteration of a boundary value, and stochastic parameter variations. Piecewise, constant velocities permit both a continuous and a discrete treatment
Comparison 13 (Crane Crab with Embedded Control, April 2001)
This comparison checks techniques and features for embedded digital control with sensors and with observersystems. The special problems are discrete control coupled with sensor diagnosis and observers and complex experiments.
Comparison 14 (Supply Chain, November 2001)
4 factories produce 12 different products which are supplied to a distributor. This comparison addresses discrete simulator - features for supply chain systems (messages, strategies). Special problems that occur are distinction between material flow and order flow and distance-dependent control strategies.
Comparison 15 (Clearance Identification, December 2002)
This comparison checks identification features (based on measured data) and influences of noise. Problems that occur are the appropriate identification algorithms, short-term input functions (Dirac-like) and the support of statistics.
Comparison 16 (Restaurant Business Dynamics, May 2004)
addresses agent-based simulation as well as DEVS approach and classical programming. Occuring special problems are the renaissance of activity scanning, coordination of run samples and optimisation.
Comparison 17 (Spatial Dynamics of SIR-Type Epidemic, December 2004)
A comparison which analyses temporal and spatial behaviour of a disease spreading process by cellular automata models. Difficulties that can be encountered are proper features for cellular automata in simulation systems and the comparison of spatial/temporal results with pure temporal results.
Comparison 18 (Neural Networks versus Transfer Functions - Identification of Nonlinear Systems, July 2005)
compares transfer function modelling and neural net modelling for given data of a nonlinear process. Special problems are proper features for neural net modelling in the simulation system and combination of transfer functions with neural nets for parameter tuning
Comparison 19 (Pollution in Groundwater Flow, December 2005)
studies the flow of contamination in the ground water in 2D-space and time and allowing different modelling approaches for the spatial behaviour (numerical PDE solution, discretisation to ODEs, cellular automata and so on). Problems that have to be considered are features for description of spatial dynamics and combination of spatial/temporal behaviour with temporal behaviour of control inputs

We invite all readers to participate in these comparisons. Please, simulate the model(s) with a tool of your choice and send a report to the editors in the following form (on diskette, any word processing format, or per email or transfer to our ftp-server):

We offer to place the full model (source code, graphics, etc.) and additional information on our WWW server. We also invite you to prepare animations. Please send files and additional information in HTML-format.

Summaries of the comparisons are presented at conferences and published from time to time in SNE. Overviews on Comparison 1 and Comparison 2 (all solutions, partly extended solutions, model descriptions, source codes and all published summaries) have been published in the series ARGESIM Report.