SAP Message V1816 - Assembly process only possible for engineer or cust. make-to-order prod.

Diagnosis
The following indicators have been determined in Customizing for itemV1:
Consumption posting indicator = '&V3&'
Special stock indicator = '&V2&'
Evaluated special stock indicator = '&V4&'
Make-to-order production is not permitted for this combination whichmeans that the assembly process for item &V1& cannot be used either.

System Response
The system terminates assembly processing for item &V1&, and anyexisting assembly orders for the schedule line are marked for deletion.

Procedure
Configure the settings in Customizing so that make-to-order productionis possible by choosing Materials Management -> Purchasing ->Account Assignment -> Maintain Account Assignment Categories.
The combinations are as follows:
(1) (2) (3) (4) (5)
Consumption posting indicator / 'E' / 'E' / ' ' / 'P' / 'P'
Special stock indicator / 'E' / 'E' / 'E' / 'E' / 'Q'
Evaluated special stock indicator / ' ' / 'M' / 'M' / ' ' / ' '