<p> IE 429 Spring 2004</p><p>Common Errors When Running Arena Model</p><p>1- Run over 100 (or 150) entities It happens when there are more than 100 entities at one time in the system (for student version). There should be a bottleneck in your model. Check you model to find it. Here is an example error message: </p><p>ERROR:</p><p>Entity: 150 A runtime error was detected at time 176.05796 at the following block:</p><p>* 1 2$ CREATE,1,HoursToBaseTime(0.0),Entity 1: HoursToBaseTime(EXPO(1)): NEXT(3$);</p><p>Maximum of 150 entities exceeded. Possible causes: - A logic problem in your model is creating too many entities or not disposing them. The run controller may be helpful in finding the problem. - You are in demo mode and have exceeded the entity limit. The commercial version is required to run large models. - You have set an entity limit on the DISCRETE element that is too small. Remove the limit or set it to a larger number. - You have exceeded the standard array space for models. Use the Array Sizes page in the Tools/Options dialog to increase the RSET space allocated and recheck your model. Common Types of reasons for this error: a) Check for time units in your model to match. b) Check for consistency of names you have selected in your model. For example do not use the same name for different purposes. Make sure your names’ spelling is consistent. c) Run your model for a shorter time, less than the error time. For example, for the above figure run your model for 170 unit of time. Check your statistical output for bottlenecks. For example entity flow is not logical in some parts of model, or there is a pile up situation at one queue. To check for pile up, look for high values of “max number in queue” and “final number in queue”, they may even be equal. d) Check for capacity of your resources.</p><p>2- Connection It happens when you try to connect wrong modules to each other.</p><p>1 3- Same name, Reserved word It happens when you select same name for Process and Resource, or select a “Reserved” word by Arena.</p><p>ERROR:</p><p>Module name must be unique.</p><p>4- Modify model through spread sheet window.</p><p>2</p>