Hi Cao,
in tcode /DBM/SPRO->Order>Order Type->Define Order Type
to each order type "GM Type Schema" is attached which decided the movement type that are used for posting goods movment based on item category .
This "GM Type Schema" can be configure and assigned to movement type on tcode /DBM/SPRO->Part->Assign Movement Types and Delivery Types.
You can keep standard or switch to based on your requirement but do not forget to add /DBM/ORDER02 transaction code to allowed transaction list to movement type else it may not work..rest their are lot difference between 502 and 601 in behvaiour both in terms of finance and logistics....like 601 is with account assignment..but 502 is not which makes sense as profitability analysis in DBM is handles at internal order level not at sales item level
my suggestion go with standard unless you have clear requirement of using different movement type..
Regards
Ganesh