Eject entity from server when failure occurs

Hi there,

On page 2-28 of the simevents documentation there is noted: "If you want to eject the current entity from the server upon a failure occurence, then you can use the preemption feature of the server to replace the current entity with a high-priority placeholder". This is a nice note, but I am unsure how to model such a situation when a failure is modeled in the same way as in the example on page 2-28 (via an entity gate)? How can the failure gate and the entity server communicate when a failure occurs and preempt the order that is processed at that moment from the server, give it a high priority and a residual processing time and send it back to the queue?

In the attachments you can find an example with explanation of what I am trying to achieve.

Thank you very much

Answer 1

[Abdolkarim Mohammadi]

Generally speaking, failures are preempted entities that does not consume resources. They are generated from another entity generator of the same type of the main entities, but are generated in another route, so that they do not acquire resources. The routes of normal entities and failures are then combined with each other via Entity Input Switch block.

[Sander van den Heuvel]

Hi Abdolkarim,

Thank you very much for taking the time to answer my question. I used your comment to revise the example I had attached, into a system that seems to work (see this attachment). Would you be so kind to take a look at this revised example to see whether this is the most efficient way to include such a scenario.

I intend to use this in a simulation model of a production facility that is rather extensive and want to model as cleanly as possible. I previously modeled the failure by using two entity gates that closed of the server at both the input as the output to be as accurately as possible. However this did not prevent an entity from entering say 1 timeunit before the failure and still complete its entire processing and then leave as soon as the failure was resolved and the entity gates opened.

Again I thank you and hopefully this will help others in the future,