3rd Party Inventory Tracking

Hello Experts,

I'm working on an implementation of DP and SNP within the SCM System, where we'll use DP to forecast our in-feed (across our 3rd party (3P) vendors) and transfer it to SNP. Once in SNP I need to net out inventory quantities, which is in a typical scenario no problem and quite easy. however, the scenario i am working doesn't seem to quite fit from what i understand and where i need some guidance.

First let me say i am looking for guidance on what documenation i could read that would help me solve my problem. Whether it be help documentation, white papers, etc.

In my organization, we have fully outsourced our operations to various 3rd party vendors, but we perform all the material planning so the material distributor(s) know how much material is going to be required to fulfill our network. The challenge i am facing is what is the best way to track the inventory levels at the various 3rd party locations? Please keep in mind we do not own nor manage the 3rd party inventory. Which means we do not perform GR or GI nor are we involved in the purchasing or selling of materials but, we need visibility into their inventory for netting in SNP. The first thought was to simply put the inventory quantities for each 3P into a BW cube and pull it from there. I haven't ruled this option out but before i committ to this i'd like to know if there is a standard solution to this problem. is there a way to store the inventory in ECC and CIF to SCM or whether storing the inventory directly in SCM. At this point i am not set on any given idea and i am really looking for a standard way to track our 3rd party inventory. one last comment is, i'm not opposed to using a standard modulel/process in a non-standard method meaning if there is a module out there that does 75 to 90 % of what i want but i have to rework somethings i'm open to that as well.

thank you in advance for taking the time to review my question.

Mike