I am in the process of modelling a flexible manufacturing system, and I am experiencing some difficulties which I hope you can help me with.
The production set-up which I am trying to model is based on 2 production machines (CNC1 & CNC2), and 1 measuring machine (CMM). There are approximately 80 different products produced at the CNC1 and 50 products produced at the CNC2. All of these products have different arrival times, and different routings between the CNC machines and the CMM machine. The routing of a product is back and forth between CNC1 and CMM or back and forth between CNC2 and CMM. Further there are different cycle times at the servers dependent on the specific product and operation. To handle the different routings and cycle times I have created a table for each.
I have attached a simple version of my model which only contains four of the products.
I am currently having difficulties with modeling three aspects:
1-Interarrival time - Is there a way to define the distributions of the interarrival times for the 150 different products and assigning a label to each product without creating 150 source atoms?
2-Server schedule - How do I define the schedule for when the servers are open? The current schedule for the 3 servers is:
- Monday to Friday – open 24/7
Saturday – closed
Sunday – open from 18:00-24:00
In the production set-up there are also supposed to be conveyors, though I have troubles figuring out how to model this. The situation is:
In the production set-up there are five conveyors between the CNC1 and the CMM, and 3 conveyors between CNC2 and the CMM.
After a product is mounted on the conveyor, the product stays on the conveyor until it has been through all the operations, as defined by the routings table. This entails that the conveyor must be seized when the product enters the system and first released for use when that specific product exists the system. This entails that WIP for CNC1 is 5 and WIP for CNC2 is 3. Further there can only be 1 product on a conveyor.
I hope you can help me with this and thank you in advance.