HI Kiran;
Thanks for the reply .
I would like to explain here in more details.
As explained in problem statement material A is semi finished , required for material B which is
Parent one.
Lot size of A is 6000 Kg and can not be changed. Due to process constraints it is needed to produce in a lot of 6000 Only . But this 6000 kg is actually partially produced in slot of 1000 Kg quantity. After 12 days of process lead time , on 17th day 1000Kg is given ,,, then on 22nd next 1000 and so on . So 1000 kg partially given to B in 5 different slots . So total lead time is 42 days.
But problem is B is not having lot size as that of A . It is required only 1000 Kg for its process order.
So if customer wants to optimize the planning for B , he can not do that due to different different supply dates of 1000Kg.
Till this period of time we have thought of following solutions but I know these will not be feasible :
Option 1 : Either we can enter 6 times material A in BOM of material B by specifying Negative lead time of each component by 25, 30 , 35 , 37 and 42 days respectively . This will surely give requirement to produce A in different past days ,, but each requirement of B is of 1000 will lead to plan the material A in 6000 due to its constrained lot size .
Option2 : We have also thought of 6 different production version , but again this will be complex from end user point of view and also above lot size issue will occur , because each time requirement of A will lead to generate 6000Kg ... which will cause Over-Extra Planning .