Comments on: Is Simulation Fake? http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/ Bruce Silver's blog on business process management Tue, 14 Oct 2008 07:50:04 +0000 http://wordpress.org/?v=2.5.1 By: BPMGuy http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-3268 BPMGuy Mon, 10 Dec 2007 11:39:56 +0000 http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-3268 Well said. People think, since the process diagram is ready, simulation is the next easy step. Actually data needed for simulation is very tedious job. I don't think BPM is designed with simulation in mind Well said. People think, since the process diagram is ready, simulation is the next easy step. Actually data needed for simulation is very tedious job. I don’t think BPM is designed with simulation in mind

]]> By: You can’t manage what you can’t measure! « Mike Letulle’s Blog http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-2357 You can’t manage what you can’t measure! « Mike Letulle’s Blog Mon, 17 Sep 2007 19:40:56 +0000 http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-2357 [...] Bruce Silver, an independent analyst who focuses on BPM, wrote a pretty interesting post about simulators back in March of this year called Is Simulation Fake? . [...] [...] Bruce Silver, an independent analyst who focuses on BPM, wrote a pretty interesting post about simulators back in March of this year called Is Simulation Fake? . [...]

]]> By: francis_ip http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-1531 francis_ip Thu, 26 Apr 2007 01:43:28 +0000 http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-1531 Dr. Bruce Silver, My first simulation project was back in 1973 at the Ministry of Transportation and Communications of Ontario, Canada, when I was a Computer Liaison Officer. I used GPSS (General Purpose Simulation System) from IBM to construct and run several simulation models for testing and implementing a computer-assisted and Operations Research based Strategic Planning System. That system was a component for implementing the PPBS (Planning, Programming, Budgeting System), which all Federal and Provincial/State governments use since 60s or 70s. DoD was the first department to use PPBS. President Johnson mandated it for every US Federal departments and agencies in 1965. The Province of Ontario adopted it since 1970. Simulation is based on a well defined activity model and sampling of real-life performance statistics. The statistical data would be analyzed with regression analyses to pick the best-fit probability distribution. Real-life data is used as a guide to calibrate the simulation model by running many iterations through a large prime number as the seed for random number generator. This is to ensure that the model does reflect the reality. The parameters of the model are then varied to test for sensitivity (i.e. 'if scenarios'). For process improvement, a new model is constructed, tested, and compared to the same set of real-life statistical data. In most cases, the activity model is constructed from several queueing models. In general, the arrival pattern follows the Poisson Distribution while the service pattern follows the Negative Exponential Distribution. For telecommunications network simulation model, the service pattern would be Erlang distribution (a specialized form of Negative Exponential Distribution). When I was on contract with Cantel (now Rogers), a cellphone service provider, as the Chief Architect in 1988 and 89, GPSS was used to assist in the design and development of cellular telephone network across Canada from coast to coast! I don't see how PBMN and BPMS, in their current forms, can really support simulation as I define above. It should be noted that I don't speak from conjectures, I speak from experiences as a practitioner of OR (Operations Research). Moreover, several BPM simulators use Triangular Distribution (which is easy to program but doesn't reflect reality) and Monte Carlo method for simulation. Monte Carlo method is used for evaluating ill-defined mathematical functions through Variance Reduction, not for simulating processes! I hope that your Ph.D. would help you to understand what I have said above. Best regards, Francis Ip Dr. Bruce Silver,

My first simulation project was back in 1973 at the Ministry of Transportation and Communications of Ontario, Canada, when I was a Computer Liaison Officer. I used GPSS (General Purpose Simulation System) from IBM to construct and run several simulation models for testing and implementing a computer-assisted and Operations Research based Strategic Planning System. That system was a component for implementing the PPBS (Planning, Programming, Budgeting System), which all Federal and Provincial/State governments use since 60s or 70s. DoD was the first department to use PPBS. President Johnson mandated it for every US Federal departments and agencies in 1965. The Province of Ontario adopted it since 1970.

Simulation is based on a well defined activity model and sampling of real-life performance statistics. The statistical data would be analyzed with regression analyses to pick the best-fit probability distribution. Real-life data is used as a guide to calibrate the simulation model by running many iterations through a large prime number as the seed for random number generator. This is to ensure that the model does reflect the reality. The parameters of the model are then varied to test for sensitivity (i.e. ‘if scenarios’). For process improvement, a new model is constructed, tested, and compared to the same set of real-life statistical data. In most cases, the activity model is constructed from several queueing models. In general, the arrival pattern follows the Poisson Distribution while the service pattern follows the Negative Exponential Distribution. For telecommunications network simulation model, the service pattern would be Erlang distribution (a specialized form of Negative Exponential Distribution). When I was on contract with Cantel (now Rogers), a cellphone service provider, as the Chief Architect in 1988 and 89, GPSS was used to assist in the design and development of cellular telephone network across Canada from coast to coast!

I don’t see how PBMN and BPMS, in their current forms, can really support simulation as I define above. It should be noted that I don’t speak from conjectures, I speak from experiences as a practitioner of OR (Operations Research). Moreover, several BPM simulators use Triangular Distribution (which is easy to program but doesn’t reflect reality) and Monte Carlo method for simulation. Monte Carlo method is used for evaluating ill-defined mathematical functions through Variance Reduction, not for simulating processes!

I hope that your Ph.D. would help you to understand what I have said above.

Best regards,
Francis Ip

]]> By: BrettChamplin http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-985 BrettChamplin Sat, 31 Mar 2007 23:00:09 +0000 http://www.brsilver.com/wordpress/2007/03/08/is-simulation-fake/#comment-985 Maybe you're using "fake" modeling tools, Bruce. Typically those tools that just produce drawings don't and can't do simulation because it takes a lot more information and more rigorous diagramming to produce any useful simulations. I for one have been using modeling tools that are capable of simulations for 10+ years and there are several tools that do. I agree with you if you are implying that unless a modeling tool is capable of serious simulation and analysis it really doesn't serve the needs of a serious business process analyst/designer. The product that I've been using for the last several years can meet all of your criteria and more - Corporate Modeler Suite by Casewise. Of course, the tool isn't really the issue anyway. The issue is whether or not you are working in an organization that will support the extra effort to develop rigorous models that let you experiment and have some degree of confidence in the designs. The real problems with doing simulations are that too often, the data necessary to create them doesn't exist and has to be "discovered" and that there are too few analysts who can create valid simulations and too few managers who understand what goes into it and the value it provides. Maybe you’re using “fake” modeling tools, Bruce. Typically those tools that just produce drawings don’t and can’t do simulation because it takes a lot more information and more rigorous diagramming to produce any useful simulations. I for one have been using modeling tools that are capable of simulations for 10+ years and there are several tools that do. I agree with you if you are implying that unless a modeling tool is capable of serious simulation and analysis it really doesn’t serve the needs of a serious business process analyst/designer. The product that I’ve been using for the last several years can meet all of your criteria and more - Corporate Modeler Suite by Casewise. Of course, the tool isn’t really the issue anyway. The issue is whether or not you are working in an organization that will support the extra effort to develop rigorous models that let you experiment and have some degree of confidence in the designs. The real problems with doing simulations are that too often, the data necessary to create them doesn’t exist and has to be “discovered” and that there are too few analysts who can create valid simulations and too few managers who understand what goes into it and the value it provides.

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