I had developed a simple Rule Policy in the Business Rule Composer, and was attempting to include it in an Orchestration using the Call Rules shape. The Policy was correctly Published and Deployed, and was available in the ‘Select the business policy’ drop-down, however, I was unable to specify any parameters to pass to the Policy. The parameters section simply did not provide any facility for mapping a local message instance to a policy parameter.
A little research revealed this post, detailing the solution.
It is important that there is no ambiguity with the schemas for messages being passed to the BRE. To this end, the BRE requires you set the Document Type name of any Schema Facts to the Fully Qualified Name (FQN) of the schema. The Fully Qualified Name can be found in the Properties of the .xsd file in Visual Studio.
Once the Document Type has been changed to use a FQN, and any Rules and/or Vocabularies appropriately updated, the Policy can be re-published, and parameters will be accessible within the Call Rules shape.