Constraint planning to distribute the demand in multiple mfg facilities based on available capacity

Summary:

Orders and forecasts are received at the distribution center, which can fulfill demand from any of the three manufacturing facilities—one owned by the company and two operated by contract manufacturers (CMs). The CMs do not maintain any on-hand inventory for finished goods; instead, they receive components from the company-owned manufacturing facility to produce the product. Our goal is to have demand fulfilled by the two CM organizations if the company-owned facility lacks capacity.

I created a global sourcing rule for the item and the distribution center, assigning all three manufacturing facilities with priority rankings: Rank 1 for the company-owned facility, followed by the two CMs as Rank 2 and Rank 3.