Hello all, I am been working on the ‘requisition methods’ post I sent some time ago. Now we have almost all the funtionality ready, but I have one problem with the send ahead quantity (SAQ) behaviour. As far as I know, this parameter would give the chance to overlap operations. If you have one lot for 10 elements, and you has a SAQ of 2, then when the first operation has finished on 2 elements, then this 2 elements goes to the next operation and so on. Then you have overlapping of operations. The first two units are finished in 1/5 of the total time for the 10 elements. The first entry of the capacity for the second work center is inmediately made after the first entry of capacity of the first work center (there are 10 entries of capacity for each center - well if the send ahead quantity for all the operations are the same). If you have only 1 size lot, then you could use the SAQ with numbers less than 1. So if SAQ is equal to 0.5, then when the 50% of the first operation is made, then you can start the second ( overlapping of operations), and so on, so the total lead time is reduced to half. But Navision does not have this behavior. It seem that what really does is to divide the lot, so you have 5 diferent lots, and almost you finish the first lot before you begin the second (well it is not exactly true, but I can not find which is the exact behavior). If you see the allocated capacity on an operation of a route of a production order, you can see that you will have 5 inputs and the starting time of the second is not the end of the first. The question is, does anybody know how this parameter works ??? How can I reduce the lead time without touching the times in the routings ?? (I calculate time, and I give the Job cards with navision) Thanks in advance and best regards from spain,
I thought the behaviour was as follows : - SAQ = 2 on operation 10, run time = 1 minute. - SAQ = 0 as of operation 20, run time = 1 minute. Production lot = 10. When the first 2 pieces are made on operation 10 (after 2 minutes), operation 20 can start => LT = 12 minutes. You could also try to use concurrent capacities (on routing), efficiency and capacity (work center & machine center card) to tweak production lead time.
Ok, I see. Well what I am trying to do is to generate automaticly one version for routings that fits the lead time that appears in the item card, without any manual correction. And of course if you change the parameters of the work center then it affects to all the routings that uses it. If you play a lot with the capacity of the work center, and adjusts the concurrent capacity in the routings lines then you will have a mess with the preparations times. I see the example, and I can understand it. But what happens if you have a third work center with SAQ = 2?? Thanks in advance,
Sorry, the SAQ = 2 in the second operation, and you add a third operaton.
Hi Diego I believe the same happens again: As Gunther explained SAQ = 2 on operation 10, run time = 1 minute. SAQ = 2 as of operation 20, run time = 1 minute. SAQ = 3 as of operation 30, run time = 1 minute. Again after 2 are completed on OP10, OP20 starts, and again as the first two of OP20 are completed OP30 starts - concatenating the whole run time. So as you start the 5th item of OP10 the first item through OP10 is started on in OP30. Obviously I have not tested this [:D]