I think one of the main issues lies in increased customer demands. When the design team first hands off the project to the manufacturing team, a certain plan is made based on the expected demand. Once the product becomes more popular and there is increased demand, rather than manufacturing just scaling up I think it may be important to include the design team in the decision on how to do this. While the manufacturing team certainly has the skillsets to scale up, the design team thinks in different ways and may come up with different valid points. This can be done by having a meeting with the two teams present whenever making a big change in the production of the product.