Comments on: Making Simulation Useful

By: wvdaalst

wvdaalst — Sun, 05 Jul 2009 19:20:22 +0000

Thanks Bruce, I agree with many of your observations. People talking about simulation features obviously have little hands-on simulation experience in real-life settings where people are involved. For example, the Yerkes-Dodson Law of Arousal can be observed in any office situation but is never supported by tools. Moreover, people are involved in so many (informal) processes that it is very difficult to simulate one process in isolation, etc.

For a study into these effects, see the following paper:

W.M.P. van der Aalst, J. Nakatumba, A. Rozinat, and N. Russell. Business Process Simulation: How to get it right? BPM Center Report BPM-08-07, BPMcenter.org, 2008.
http://is.tm.tue.nl/staff/wvda.....-08-07.pdf

It lists these problems, and identifies the effect of some of these phenomena.

Cheers, Wil.

By: Lanner

Lanner — Mon, 23 Mar 2009 10:18:59 +0000

Lanner supplies L-SIM a JAVA component specific for simulation of BPMN, we have been involved in simulation for years and so fully endorse the power and usefulness of the technique.

L_SIM can support all the points raised by Bruce….we also advise partners on how to implement it properly. We feel the key is for BPMS vendors is to use a proper simulation engine and provide users with the necessary capability.

L-SIM is used inside ARIS by IDS Scheer, so we appreciate IVO’s comments!

By: bruce

bruce — Thu, 05 Mar 2009 19:42:22 +0000

Colin,
Good to hear from you. I’ll take you up on the demo. (I should have added another thing… don’t require a BAM runtime to get model simulation.) I also agree with you (and others) that users don’t understand enough about either their own processes or how to use simulation to do simulation effectively. But it’s a chicken and egg problem. Until the tools are good, users won’t know how to use them. So fixing the tools, unfortunately, comes first. (Welcome to the hard realities of a BPMS vendor!)

I’m not sure I understand your prepopulation scenario. The issue is not starting after simulation has run for a while. It’s starting from the current actual condition, and simulating from there. Can G360 do that? If so, that’s great.
–Bruce

By: cteubner

cteubner — Thu, 05 Mar 2009 19:11:11 +0000

Hi Bruce -
I certainly agree with your basic premise, but am compelled to point out that Global 360’s simulator (part of our Insight360 product) offers all the features you describe. The possible exception is contingent resource assignment, which doesn’t work exactly as you described it, but I think we can achieve the same effect. I’m happy to arrange a demo sometime if you like.

I’d also argue that prepopulation of backlogs isn’t really necessary if you have the raw output described in your last bullet – you can simply perform your analysis on any given window of output, including one that starts after the simulation has been running for a while.

The problem with simulation, in my opinion, lies in most businesses’ lack of understanding of their processes. This makes coming up with parameters for the baseline simulation scenario very difficult. We can use production data for this, but you run into the classic problem: differences between implementation models and the business model that simulation-running analysts care about.

I think the root cause of this issue is simply an overall immaturity of BPM efforts. Only now are we starting to see the more advanced BPM practitioners really use simulation, and as you suggest, it can be a very powerful tool for change impact analysis.
Regards
Colin Teubner

By: ivo

ivo — Tue, 03 Mar 2009 13:32:42 +0000

Bruce,

I fully agree with your 7 points. However, there are tools that support most of them if not all. I personally have experience with ARIS Business Simulator and it supports these 7 and many more. (I do not represent the vendor in any capacity, I’m just a user.) The information posted on the web – http://www.ids-scheer.com/en/A...../5289.html – is quite a bad marketing compared to other vendors but is some starting point anyway.

Regards

Ivo

By: sfrancis

sfrancis — Mon, 16 Feb 2009 03:10:37 +0000

Bruce,
another great summation of a major shortcoming of existing simulation tools on the market. In general, they all suffer from varying degrees of these problems – and the traditional problem of “bad data in, bad data out” – if you are simulating a process and putting in the data and probabilities but can’t be assured that those are based on “real world” values, then how valuable can the simulation really be?

I especially like your point about event probability/occurrence – this typically isn’t handled at all by simulation tools and for SOME models that renders the simulation completely useless.

For instance properties – I have seen simulations take into account real-world probabilities/correlations in the simulation – but without starting from real-world measured data, the data entry becomes simply overwhelming except on toy models. I would label that point really “correlation of properties to outcomes” rather than just instance properties…

I have worked with a tool that provides pre-loading the data -either data that is generated from the simulation (essentially “simulating” a process load that might be 3-6 months after starting the process from zero), or by using a real point in time, making a change, and simulating from that point as the starting point (with in-flight instances, etc).

I still find that, in general, real-world BPM models are a little too complicated for the real-world simulation software- though I have been impressed by the progress of just one or two of the vendors in terms of their progress on this score, and I think the simulations that take into account REAL data are a big step up to those that depend on manually inputted data.

By: frenchdk

frenchdk — Mon, 16 Feb 2009 01:06:29 +0000

At the risk of creating another execute v transform argument, I suggest that an effective simulation strategy would be take an existing simulation tool and transform the BPMN model into it. Of course, that might be easier when there is a BPMN schema.
Apart from the analysis available from simulation, complex processes can be animated in the simulation tool which can save a lot of hand waving in from of an abstract BPMN diagram.