Great discussion, guys! I think a hybrid of the above suggested alternatives would be a good idea.
1. Model (common) Business Object in Workflow Designer.2. Implement generic Toolkit uitlility to CRUD and serialize/deserialize BO to/from JSON. Perpahs with metadata such as schema version, location etc. Persist in CPE (let client decide where).3. Reuse Toolkit across solutions. Persist/share BOs on the desired scope (customer level, parent case, current case, current process/activity, etc).The usual schema evolution concerns apply here as well, and can be added to existing solution development practices - ie, if you change BO YXZ, make sure to also address forward/backward compatibility and/or migration concerns.Persistence mechanism above can of course be pluggable, but to me it makes the most sense to persist as close to the case as possible, at the desired scope (customer level, parent case, current case/process/activity). FileNet supports both optimistic and pessimistic locking, so I'd suggest using that when appropriate.