1. Apparatus for configuring a process control system, the apparatus comprising: a plurality of objects, each object representing an entity, and each object being associated with an object type, at least one object (“connection” object) identifying permissible combinations of object types that can form any of a parent/child relationship, a source/sink relationship, and other relationship, the apparatus validating a potential relationship between objects by comparing the object types with which they are associated with permissible relationships identified by the connection object.