No, I'm not sure. I think this area is one many OFBiz adopters will want to customise. What I'm contemplating is a simple example implementation, and support in the data model so it would be fairly easy to write a customised service to assign parties to a routing task.
You have implemented OFBiz in a manufacturing situation, so if you think there's no prospect for a simple implementation, I'd be happy to accept your advice.
What really got me going on this was
OFBIZ-5852. It is absolutely better than nothing, but won't scale. Associating a fixed party with a task means when that party is unavailable, there can be no automatic assignment at all. In contrast, if the assignment is skills based, when a party goes on leave or ceases to work for the organisation, the service can assign or suggest another party with appropriate skills.
In the default implementation in OFBiz, I would be happy if the skills associated with the task are used to filter a list of parties, so only parties with the appropriate skills are offered to the production manager. If there are no skills, allow the production manager to browse all parties. Where skills have been set up, perhaps offer a list of parties filtered by skills first, with the ability to browse all parties if that's what the production manager wants to do.
You say a production manager would only be able to assign parties that he or she can direct, members of a team over which the manager has some authority. So maybe the filter would not just be on skills. If we attach a party filter to a task to narrow down parties that might possibly perform it, we should think about criteria. Membership of a PartyGroup (a team or department) would be one, skills would be another. Are there any more we can think of?