How to model failures and preemption in fluid library

Question

I will use the Fluid Pickup example from AnyLogic to explain my question. Let's say we have a pump (resource) that needs to be available for the cars to pickup fluid. We can add a seize and release before and after the pickup block and model this. Next step is to allow the pump to fail. The question is what is going to happen to a car that has already started picking up fluid:

1. How can we stop the flow when the pump fails? (probably use failure flowchart and close the valve)
2. How can we force the car to leave the pump with the current amount picked up? (not wait until Fluid to pickup is completed)
3. Similarly, if the tank is small and is being continuously filled by a pump and that pump fails, the car needs to leave with whatever it has picked up (In this case, the flow to the car will become 0 so the first question is answered but the second one exists)

Thanks

Answer 1

You will have to create your own resource agent that acts as a pump without using the fluid pickup block.

The pick up block is not very difficult to model on your own, since it's just moving fluid from your resource to the agent that needs the fluid (using fluid enter and fluid exit blocks).

With that being said, you will have a resource that works as any other with failures... and you can create the logic to do something with the agent that didn't get all the fluid it wanted.

Summary: This may be a bit too much to show you a full working model here, but the take away lesson here is not to use the fluid pickup block. Instead have the source of the fluid inside your resource (since your resource is the pump) and move it with fluid enter and exit blocks.