Arrange a sequence of activities at the same simulation time

[anggoro_p]

Hi, I made a process flow of 3 main entities: plant, warehouse, and customer. The plant supplies products to warehouse with delay = 1 day. Meanwhile, customers order directly to warehouse (no delay). I used a list for representing the warehouse, thus corresponding push and pull activities are required to and from the list.

I wonder what will happen if for example at time = 1 (in day) there are some products need to be pushed to the list. At the same time, there are some orders need to be satisfied. Because both activities have the same simulation time, how FlexSim simulates these two activities? Which one will be run first?

I intend to create a sequence within a day. First, in the morning products from the plant arrives. Then in the afternoon, order comes and warehouse satisfies this request. And in the end of the day, inventory level is checked.

Do you have any tricks to model such a sequence within a day? Or how to manage the occurrence of some activities on the same day? Because in the end, it will affect the performance of system. Thanks

[raja_sekaran · Accepted solution]

Hi @Anggoro P

Try to hold the token for a certain length of time using delay activity before the push to list and pull from the list as shown in the pic below.

I hope this is what you are looking for.

Thanks.

schedule-arrival-support.fsm

[anggoro_p]

Ok, I will try that way! Thus also for checking end inventory, I could add delay for example 0.9, couldn't I? Thanks so much

[raja_sekaran]

@Anggoro P

You can create token at the interarrival time of 1 to get the inventory level. No need to add delay to this one.

support.fsm

[mischa_spelt]

Usually, pushing something onto a list will cause the backorders to be re-evaluated against the pushed value. So if you would build the flow as depicted by @Raja Sekaran without the delays, then create a puller and push multiple values onto the list, the puller would get the first pushed value.

The list has an option that will make pullers wait for any other push values at the same time.

If you check this option on the Back Orders tab of the list's properties, you can safely push multiple values at the same simulation time and they will all be considered by a puller.

In addition there is a checkbox "Reevaluate all values on push" which will make pullers also consider values that were already on the list. This is useful if you are using dynamic fields, for example "Order released" which may change while values are on the list. It can happen that an order which was unavailable before now does match your query, checking this box will make sure that whenever something is pushed to the list not just the new value(s) is/are evaluated, but also all the values already present.

[anggoro_p]

@Mischa Spelt

Yes, backorder option could be an option. However, I have to deal with a system without backorder (once the list cannot satisfy the puller, then lost sales occurs). Thus I think adding slightly delay would be better to represent the real world