Task Executer Priority

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question

Ben O asked Apr 17, '18 Jeff Nordgren answered Sep 24, '19

Task Executer Priority

Sorry if this seems really basic, but all I want is for a single task executer (crane in this case) to be used for all transport along a factory line, then when it breaks down (from MTBF), another crane is used while the original is under repair.

I have made a label "Broken Down" which has a default value of 1, then using SetLabel it becomes 2 when the crane is broken down. I then use the expression:

getlabel(outobject(current, 1), "Broken Down")

as the "Pass To" expression.

With this in place, and Crane1 in the first dispatcher output port (current, 1), and Crane2 in the second (current, 2), I would expect the first crane to be used at all times it is not broken down as the label "Broken Down"=1 and therefore getlabel(outobject(current, 1), "Broken Down")=1, and when broken down the opposite is true, and Crane2 is used instead.

Unfortunately this is not the case, and Crane2 does nothing when Crane1 is broken down.

Please could someone tell me of an easier way to ensure Crane2 only operates when Crane1 is broken down?

Many thanks in advance.

Software Version:

FlexSim 16.2.2

task executer crane mtbf mttr breakdown prioritization

Answer 1 · 2018-04-17T21:48:54Z

Jeff Nordgren answered Apr 17, '18

@Ben O

The way I would do it is to have both cranes connected but have the "reserve" crane input port closed. Then when needed, open the input port of the reserve crane. When not needed anymore, close the input port. You also need an "A" connection from the crane back to a dispatcher so that when it goes down, it can pass the unfinished task back to the dispatcher to send to the reserve crane. In fact, maybe I would use the stopobject() command for the reserve crane instead of just closing/opening the input port. Start the reserve crane "stopped" and when needed, "start" the reserve crane and visa vera.

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