Modeling usage of technical resources for simulation

Diana Bozic on August 4, 2012

Hi there,

I have following situation in my model:

a) I have 5 positions for truck

b) daily frequency of start event is 12 (truck on ramp)

c) when truck is on position function - unload can start and it takes 1 hour

d) at the same moment it can be max 5 truck waiting to be unload, but only one can use function -unload at one time

So, I tried to use general resource and "is consumed" but, there is no indication that function-unload is waiting (for other 4) because the lack of resources.

Does anyone have any idea? How to solve this with the use of technical resources?

Thanks

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7 Replies

Ivo Velitchkov on August 7, 2012 - 22:57

Diana,

Not knowing the simulation objectives, the easiest solution seems to be having truck as process folder instead of general resource.

Ivo

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Geoff Hook on August 7, 2012 - 23:42

I agree with Ivo, a truck should be a process folder, the number that can unload simultaneously can be constrained by the use of resources.

Geoff

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Diana Bozic Author on August 8, 2012 - 17:07

Ivo,

well I am quite new in ARIS enviroment so .. Well what I want to do is to see utilatization of warehousemans and warehouse equipment when changing the number of unloading ramps and so on..

For example: I have 3 warehousemans and 3 forklift for unloading trucks. Unloading 1 truck takes 1 houre and need at least 1 warehouseman and 1 forklift.

There are 5 ramps availabe for unloading. Truck can park on ramp which is free, and there it can wait for warehouseman to be free for unloading.

I tried to do as you said but.. probably do not understand..can you give me the hint in picture?

Trucks arrive avrg. 12 per day, that is why I use truck arivalls as start event with frequency 12, and for one ramp my simulation works very well.

Thx

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Ivo Velitchkov on August 8, 2012 - 18:26

Diana,

If trucks are treated as process folder (token), you can make you analysis related to them using process folder simulation result attributes of events and functions. There is plenty of statistical information you can monitor for each run.

General resource and Product/Service are specific resources called “capacity resource”. Activities (functions) can both decrease and increase their capacity.

You can use operating resource type, for example, Transport system, for forklifts.

Hope that helps a bit more.

Ivo

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Diana Bozic Author on August 13, 2012 - 13:10

Hy there,

thx for hints..it is working ok. But now I have one more question. I have two EPC. One has at start event 12 trucks (daily frequency) and for second EPC I put 96 shipments at start event ( one truck carries 8 shipments). As same resources are used to handle both EPC, is it possible somehow to connect them. I tried to use ERM attribute conditions hoping I can get end event of first EPC to have 96 shipments..but no luck.

Diana

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Ivo Velitchkov on August 13, 2012 - 14:51

To run them at once you need to have at least one shared (same definition) or synchronised (shared superior event modelled in Event diagram) starting event, assuming the two processes run in parallel. If you have different things flowing, trucks and shipments, you might experience some difficulties. I haven't done such simulations but I can imagine that even if you carefully model instantiations and batch jobs, and you don't have an activity that can process two types of things, you'll at least end up having different process-levels statistics so you have to check each time the staring instance to know, for example, if this is a track throughput time or a shipment throughput time. Can't you really have the same thing for both, for example shipments?

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Diana Bozic Author on August 13, 2012 - 18:25

I tried to use just shipments, but had problems with first EPC -ramp utilization and HR utilization, that is why I created two EPC. I am tring to simulate process of receiving and distribution of goods at terminal. In firts parth (EPC with trucks) all resources (ramps, equipment, people) are in fact loaded with frequency of truck arrivals. After that, some of same resources are loaded with number of shipments in each truck. If I want to see totall degree of utilization for human resource that is working on different activities in both EPC I do not know how

If only there is something to change output value of last activity..

For the forklift utilization I used ERM attr.conditions in firs EPC and it is ok.

If I use shipments also for first EPC how can I tell for example that 8 shipments (one truck) use one ramp?

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