topic Re: Sink Pull Strategy in FlexSim Forum

Sink Pull Strategy

demetre_t — Thu, 28 Dec 2017 20:32:43 GMT

[ FlexSim 17.2.4 ]

Hi,

I am relatively new to Simulating models using Flexsim so I have gone through most of the tutorials to help familiarize myself with Flexsim’s capabilities.

I am trying to create a model where the Source and connected Queue are always at maximum content, and the Sink dictates when the demand and pull occurs. Ideally I would like to use a constant figure for this demand.

I have searched through the Q&A section and have not found anything that matches what I am looking for. I saw a question from Ajay Bhesaniya on Jun 09, 2016 that describes using a Global Table for Demand where Sam Stubbs responded and came up with a solution.

I tried simulating this solution by modeling the same Global Table, Source Triggers, Sink Triggers for closing inputs, Global Variable, and User Event but I am unable to create a model that successfully created a pull demand from the sink.

My model is simpler than the one Ajay submitted where only 1 item type is created and an AGV is used to transport from the Queue to the Sink. It would be ideal to choose some sort of pull strategy based on a statistical distribution (similar to the source inter-arrival times).

Any input or advice is appreciated. Thank you.

sink-pull-demand-question.fsm

Re: Sink Pull Strategy

m_rosadini — Fri, 29 Dec 2017 09:00:50 GMT

Hi Demetre,

in the attached model, the sink closes it's input on reset and everytime a token enters the process flow it would "pull" one item. You can change the source that generates the tokens to be a table, interarrival, event triggered or whatever you need. Hope is what you were looking for

(you'll need FlexSim 2018 to open it)

support-sink.fsm

Re: Sink Pull Strategy

gilbertjerald1993 — Tue, 02 Jan 2018 10:37:18 GMT

@Demetre T

Hi,

Asper your question I have corrected your model to function according to your constraints. For the better function of the model, I have done some changes in User Events, and Entry of Sink, and some customized work in AGV Templates.

The model will work as follows:

For every 500 mins the Agv will transport the required quantity of an item from the queue to satisfied the demand (as per in the Demand global table) of sink.

The changes that are done in AGV templates are highlighted in the below fig:

I have attached the corrected model for your reference have a look on it.

Thank you

corrected-model-sink-pull-demand.fsm

Re: Sink Pull Strategy

demetre_t — Tue, 02 Jan 2018 17:51:14 GMT

@marcello.rosadini

and @gilbert jerald

Thank you both for your help. Gilbert your model was able to create to pull strategy that I was looking for. I appreciate your solution.