Answered

Normal distribution and failed simulation

First, I'd like to thanks for providing such a great tool.

In the attached model, I had a problem running simulation when I set parameters for the normal distribution. For instance, when I set the processing time of "Pack the pizza" activity with mean = 3 and sd = 1. The system showed "the simulation has failed. Please ensure that your model is compliant to the BPMN2.0 standard and that it is supported by the simulation" However, when I changed it to the following settings (mean = 5/sd=1 or mean =1/sd=0.1), the model worked well. Since I couldn't find any detailed error logs for the runtime operation, can you please check what the specific problem is? My assumption is that under the normal distribution of mean =3 and sd=1, there is a possibility of generating a negative value (P(X<=0) = 0.0013 according to http://www.mathportal.org/calculators/statistics-calculator/normal-distribution-calculator.php), which in turn causes problems. If this is the case, what would be your suggestion to model a distribution with larger variances? Thank you for your help in advance. Much appreciated!

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Dear Alder,

We will analyze this issue. As soon as possible, we will write back.

Regards

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Dear Alder,

After our analysis. you are correct. Simulation fails because the normal distribution generate negative values during the time. Our recommendation is to use a truncated normal distribution with a minimum value very small or zero to avoid negative values.

Regards