I found this article to be somewhat informative. I understand that your an engineer and that you receive designs from industrial designers that are not fully engineered and ready for tooling, manufacturing and production. The reason for this is because industrial designers are not mechanical engineers.
A better way to look at this is from the clients perspective. A proper product development company will offer both industrial design and product engineering services as one package. Ideally, the design team would be working directly with the engineering team to ensure the product that's manufactured is the same product that was introduced to the client during the final design phases.
I would say that nearly all reputable design firms will be able to offer you this service as a complete package. Some of the best design firms can also offer in-house prototyping services and may even be able to offer assistance in getting your product through tooling and manufacturing with either foreign or domestic manufacturing partners.
JAM-Proactive offers all of these services.
Edited by ibsystems on 11/07/11 11:45 AM.