Designing and fabricating a basic prototype was much harder than they had expected, and they spoke wearily of the process of obtaining permission from Apple to sell the case as a licensed accessory.
I am glad I keep reading this articles. I am reminded many times that people underestimate the manufacturing end of the product. It is great fun designing, marketing and branding, but hey you finally have to make the thing since you promised to deliver it. That is where the fun really is. At the last New York Hardware Meetup it was a abundantly clear from the panel that the manufacturing planing was a key thing that was underestimated.
Manufacturing plan is very important. The other item left out is DFM (Design For Manufacturability). People have forgotten about this too. Not forgot, but did not know they need to know that this is part of the product development and manufacturing process. The DFM process makes sure that your product is manufacturable. Without it you have no way of knowing if your product is manufacturable. It is best to keep DFM in mind when you are prototyping your product. That being said, there are many variables when it comes to DFM. In a nutshell you need to work with a person that has the skills and experience working with a factory to know what those variables are.