MRP calculation and Net Change versus Regenerative

We are running BPCS V 6.1 GA without any BMR but with a lot of own 
modifications but the MRP programs haven't been touched by this 
modifications.

We are (once more) intending to improve the MRP usage of our BPCS. In 
general the MRP works well if all parameter / conditions are properly set 
up.


First issue:
Currently we face the following issue. Our central sourcing dept. would 
like to use only annual purchase order for raw metals e.g. a huge quantity 
to supply the yearly demand in one PO line on one due date. 
I did some tests in our TRAINING environment and BPCS MRP is reacting as 
follows (depending on stock situation) if the 

PO is settled up for Jan 1st. the requirements are decreasing the PO 
quantity through the year, and there is no other MRP action.
PO is settled up for Dec. 31st. the projected on hand is going negative 
until the PO due date is reached, and there is also no other MRP action.

PO is settled up with PO line per period (weekly/monthly) the projected 
stock on hand will be balanced per due date of the PO lines, but there is 
no MRP message.

Following our expericend from shop order/planned order I was expecting 
that some MRP messages e.g. Cancel, De-expedite, Expedite, LT Violation, 
Past Due or Release.  But none of them came up after the MRP calculation 
run (MRP600) for the P.O. mentioned before.
-- the PO have been created via PUR152 as scheduled ones for raw material.

Secondly:
The difference between Net Change and Regenerative is that only items 
which need to be re-planned are treated during the Net Change. For me the 
result should be the same. If there is any need to change, the MRP will 
propose to act. The difference might be that "R" will crate new records in 
KFP/KMR and "N" will keep those which haven't any different order/demand 
situation as before and I guess that this is implicated by the Activity 
flag (see MRP300) or am I wrong.

Thanks for any tip/advice concerning the above.

rgds/mfg
Hans-Georg Loef
Impress
central MIS
Bahnhofstr. 16-17
56575 Weissenthurm
Phone: +49 (0)172 516 36 45
e-mail: hans.g.loef@xxxxxxxxxxxxxxxx

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Discover Impress on http://www.impressgroup.com
 
The  information  contained  in this e-mail and any attachments is 
strictly confidential  and  may be legally privileged.
It is intended solely for the use of the individual or entity to whom it 
is addressed. If you are not the named  addressee,
you are hereby notified that  it is prohibited and may be unlawful  to 
disclose, distribute, store, copy the information in 
any medium or usage for another purpose.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------