This post will cover API ego_item_pub.assign_item_to_org used to assign item to an organization.
Step by step demonstration of code.
Please download attached file to use as sample code. This sample code assign single item at a time to single organization you can modify it for multiple items or multiple organizations at a time.
This API assigns a specific item to any inventory organization. The item to be assigned must already assigned to parent organization before running this API.
P_param1 pass inventory item id.
P_organization_id organization id to which you want to assign item
P_organization_code organization code of specific organization
Variables need to be assign values by you.
l_user_id your used id
l_resp_id your responsibility id
l_application_id application id
Get this information from fnd_responsibility table.
Running attached code I recommend to run it initially for some items and verify that these items are assigned to specific organizations.