A process model must be associated with a set of Bindings that can be used to resolve step names and placeholders. The process designer should provide suitable bindings on the process model node, and document which ones can sensibly be overridden.
Bindings are not applied by the process model itself, but should be used when later building the process.
The Copy Sub Process Bindings derivation is used on process model node types to copy bindings from sub processes. Bindings on a main process override those on a sub process.