How to get stats on rack slots?

[amy_milesB7Q7X]

[ FlexSim 22.2.1 ]

How can i get stats on my warehouse drive in racks? Looking for max slots used at any time and avg to help size the amount of storage we need. I see the normal content stats but with having to segregate my sku, there are holes you can't use so I don't want to just use max contents.

[moehlmann_fe · Accepted solution]

You will have to build a Statistics Collector or other logic to collect that data.

You can use querySlots() to get the number of used slots. Though in order to measure the average number of used slots you will have to do this every time an item enters or exits a slot. Depending on the number of slots, this can become quite expensive in terms of computing resources, so I would suggest to instead store the value of currently used slots somewhere (a label or as part of the Statistics Collector table) and simply increment/decrement it whenever the first item enters a slot or the last item leaves a slot.

For the average, you can add up the time for which slots had at least one item in them, summed up over all slots inside a rack. So you essentially get a "SlotSeconds" value (X slots were active for Y seconds -> XY SlotSeconds. By dividing this by the total model time, you get the average number of occupied slots. Again, this can be done by storing the previous value and adding to it whenever the number of currently used slots updates. Or by using a kinetic tracked variable (for example as a label), whose rate is always equal to the current number of active slots.

Both approaches (StatisticsCollector and Labels on Rack1) are demonstrated in the attached model. The collector listens to slot entries/exits in the "Racks" group. The labels of Rack1 are updated in its triggers.

SlotStats.fsm

[amy_milesB7Q7X]

Thanks Felix, I'll try this. Any chance you could save that in 22.1? Sorry I picked the wrong version

[amy_milesB7Q7X]

I was able to upgrade my version. I tried both methods, it's all over my head but i'm getting the same values as the general stats. I do get an error on the onentry/exit trigger, but if i could figure that out and figure out how to refer to the whole row, I think I could modify it. I think this is counting slots as a single pallet location, i want the whole row to be counted as a "slot". So this example, I'd want to see "2" because I'm using 2 "slots"...maybe my definition is off but that's what i'm trying to determine. Once I get 1 pallet in, i would count that as "1", then if it goes to empty, a "0". Since we can't mix what goes in a single row(slot) I will end up with "holes" but need to account for all that in determining how much storage we need. Hope that makes sense.

[moehlmann_fe]

Could you upload your model, or at least the part with the rack where you tried to replicate the logic?

It's hard to diagnose anything from just a screenshot without knowing how the rack dimensions/slots are set up.

[amy_milesB7Q7X]

WIP_Storage_61.fsm I did figure out the tracked variable was causing the error so it's commented out right now. I'm just looking for stats on the WIP storage rack, not the others.

[moehlmann_fe]

The statistics collector is missing the condition to only trigger on the first entry into a slot or when the last item exits (compare to the if-condition in the rack triggers).

And the label "SlotSeconds" is not actually set up as a Tracked Variable yet.

[amy_milesB7Q7X]

Oh thank you so much! Works perfect now! That would be a nice feature to have built in!

[Ashish3]

Hi Felix,

What if more than one items are unloaded at a time.

In that case how do we get the stats.

[moehlmann_fe]

The demonstrated methods are providing a count of used slots, meaning slots with at least one item. They will work the same if multiple items are moved into the rack at time, since only the first item to enter a slot is counted anyway.

[Ashish3]

When using a move object activity, each item the items are loaded into the rack/floor storage, the on slot entry gets executed and along with that SlotsInUse label gets increment.

[moehlmann_fe]

Not in the model I uploaded. That is what the if-condition is for: Only run the rest of the code if the entering/exiting item is the first/last item in the slot.