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• An article by Kathryn Hoad on Obtaining Accurate Simulation Results
• Some Hints and Tips on using SIMUL8
• And details on the New Release SIMUL8 2006

Obtaining Accurate Simulation Results by Kathryn Hoad of Warwick Business School

Complete Kathryn's Survey

Even if your simulation model is completely accurate if you don't use it properly you can get inaccurate results. If your simulation results aren't accurate then they won't provide a good prediction of what would happen in the real life system. The results could be biased and misleading, with the consequence that incorrect conclusions could be drawn.

There are many decisions that need to be made about how a simulation model should be run. These include:

• Do I need to use a warm-up period; set initial conditions; or perhaps use a combination of both; or do I in fact want my simulation to start from empty ?

• If I do use a warm-up period how long should this period be ?

• Should I perform one long simulation run, or a number of independent runs (i.e. runs with different random streams,trials) ?

• How long should this one simulation run be ?

• How many replications is enough ?

In particular, the decisions on run-length, number of replications to perform in a trial and warm-up length require some knowledge of statistics. Because of the variety and complexity of statistical methods used to make informed decisions on these matters, at the moment, most simulation software provides little or no guidance to users on making these important decisions.

As the setting of inappropriate run-lengths, replication numbers and warm-up periods can lead to inaccurate and misleading results, it is considered important to deliver tools to simulation users that allow them to make informed decisions regarding these matters, whatever their statistical background.

It is with this in mind that Warwick Business School (UK) and SIMUL8 are collaborating on a project that aims to create an automated tool that can analyst preliminary simulation output and hence provide recommendations on warm-up, run-length and number of replications.

It would greatly help us with this project if you could spend just a moment of your time completing our short survey.

We don't want to bias the survey by explaining how to make these decisions yourself just now! So in the next few newsletters we'll discuss the importance of such factors more and describe how to make the right decisions.

Hints and Tips

• If you want to give several simulation objects the same name use Visual Logic to set the 'Short Names' property of the object.
• Instead of trying to find your way back to a Visual Logic line set a bookmark (just press crtl+shift+1 - or any other number from 0-9 to set any of the bookmark positions). Then by pressing ctrl + bookmark number you'll be instantly taken there.

SIMUL8 2006 Released

SIMUL8 2006 is now available. Here are the top 10 reasons why you should upgrade:

1. Scenario Runner
   
2. Data Graphics
   
3. Export Results to Word Template
   
4. Sensitivity Analysis
   
5. Macro Recorder
   
6. Improved Charts
   
7. Dashboard
   
8. Increase Trial Accuracy
   
9. Information Store Usability
   
10. Create Your Own Random Number Generator

For more details on these features check out our online Feature Guide.

If you have any questions generated from, or comments about this newsletter then email Newsletter@SIMUL8.com