Dear Experts,

I have a situation where I have a material in LTP set to use Gross Requirements planning and each month I have 3 PIR's loaded for 3 different production versions.

Each version has same validity dates and the same lot sizes defined.

When MRP runs the planned orders are created to cover the demand but they do not respect the distribution of production versions in the PIR's. It is not obvious what distribution it is using.

Example

Material: Mat001

Production versions N848, P847, P901

Fixed lot size 1000 units

For the next 7 months I have PIR's loaded for Mat001

N848, 3000 units

P847, 4000 units

P901, 5000 units

When I run MRP I get 12 planned orders for 1000 units in each month 1 - 5 all for P847

In month 6 - 7 I get 12 planned orders for 1000 units all for N848.

I get no planned orders for P901

(I have examples where a third and forth PV gets planned orders, but in each case the full months appears to be limited to a single PV)

I expected to get the following distribution each month

3 planned orders of 1000 for N848

4 planned orders of 1000 for P847

5 planned orders for 1000 for P901.

I have tried both 1 and 2 in the individual collective flag, and the material was set to 40 in planning strategy but I have tested with 11. I have also experimented with lot sizing on MRP1.

I do not want to use a quota as although the example above have fixed ratio's in all 7 months the reality is that they will often change month to month. I believe the logic was working at some point in the past but I have no evidence to back this up.

I see the same behaviour in standard MRP as well as LTP but am focused on LTP is that is where I am mostly feeling the pain.

Any idea's of what I could try and why MRP is not respecting the PV's (I also do not understand what distribution is being applied as I do get planned orders for different PV's but what triggers it to switch is not obvious),

Thanks,