Hi David,
Use Planning strategy as 50 -Planning without Final Assembly. Maintain Ind/coll indicator as 2 in MRP4 view for all the Raw Materials.
Strategy 50 is combination of MTS and MTO. You have to maintain the demand PIR for the finished material in MD61. When MRP is executed unconvertable planned orders of type VP are generated for the finished product and its sub-assemblies. For raw materials Purchase Requsition gets created since we maintain Ind/coll indicator as 2.
Once Sales order is created and MRP is executed MD50 then convertable planned order gets created for the sales order demand qty therafter subsequently production cycle starts. All the production orders created against sales order will have account assignment category as sales order number. So prduction cycle is similar to MTO.
Once Sales order is created PIR is reduced in MD04 screen and actual PIR is consumed from the MD61 table after delivery of the sales order.
Read Below for more details.
Demand driven Planning with MTO Production(Stg:50)
http://help.sap.com/saphelp_46c/helpdata/en/cb/7f93f343b711d189410000e829fbbd/content.htm
Thanks & Regards,
Ramagiri
