HOW TO MOVE PIECES IN A SERIAL MANUFACTURING WITH SPECIFIC CONDITIONS.

[CarlosAlberto1986]

Hello everyone! Firstly, i would like to thank you for accepting me on this forum. I really will appreciate your support in order to solve a situation in my simulation model, i have searched any similar situation but i haven`t succeded.

The situation is as follows: I have a server called "corte" that depends on 2 previous servers called "enfriados", these 2 servers in turn rely on 3 previous so-called "piso forja". The condition is that the server "corte" needs to be unoccupied to send to bring parts of any of the 2 previous servers, taking into account the one that takes more time processing. These 2 servers depend on the 3 previous servers so that any of the 3 that have more pieces can enter any of the 2 servers to be processed. (To understand it better I uploaded my model).

I tried some processes with loops which are executed in each of the output node if they are idle to pass the pieces, but I have not achieved any success in it. I appreciate your attention and I hope to get some recommendation to carry it out, God bless you. Greetings from Orizaba, Veracruz, Mexico.

Carlos A. Martinez

ExperimentoBucleV1.spfx

[dsturrock]

Most simulations are "push" -- as soon as a part is done, it pushes on to the next server where it waits for processing. It sounds like here you are looking for a "pull" system -- each part remains where it is at until it is pulled forward to the next server.

There are several ways to implement a push system - detailed process logic is probably the most difficult. A better choice is generally to use a resource or event to control the timing. Exactly where parts wait can have a significant effect on the logic required. For example should the part be blocking its current server? wait in its output buffer? wait somewhere else? When you have parts waiting in multiple areas it gets a bit more complicated.

--SimBit CONWIP is not exactly what you are looking to do, but it does illustrate how to use events to implement a pull system.

--SimBit OverflowWIP illustrates using resources to pull appropriate parts from one of two locations to one of two locations, as needed.

--Because you have parts waiting in multiple areas to go to multiple areas, you might want to use a slightly more advanced feature named CustomRoutingGroups. There is a SimBit of the same name. Esentially you will create a RoutingGroup (an element) to define what choices an entity can consider, ranking, and the conditions under which it moves forward. Then for each related node (like the two enfriados outputnodes, you specify EntityDestination to be that custom routing group. One key is to make sure you use the Blocked Destination Rule of Select Available Only -- this forces the entity to wait at the node until it is "pulled" forward to an available server or queue location.

For any of these approaches I suggest you read up on it in help or a textbook, then review the SimBit.

Happy modeling!

[dsturrock]

To get you started I changed the right side of your model to make it do what I think you wanted at the last 2 sets of servers. The RoutingGroups you needed were pretty simple.

I didn't work back any further to the left because I didn't know what you were doing with the infinite capacities and 0 processing times.ExperimentoBucleV1.spfx

[CarlosAlberto1986]

Thank you very much for your kind help, for sharing your knowledge with me. Actually i am working with lean manufacturing and lean thinking as well, and i will work on your advice. Concerning the infinite capacities and 0 processing times, i am traying to represent an storage space where pieces will stay storaged until they are pulled for the next precess (enfriados). I am indeed thankful to you. God bless you!

Carlos Alberto