In that case, I would have prefered a non-merged system if I were you. Because, implementing a system has lots of hard paths to walk, and in this case, there are 3 different companies, different manufacturing processes, different managers, different quality cultures and approaches, a separate managing level... The worst thing I always encounter is the human factor; you must achieve the leadership of the top management and the involvement of the people at the same time. When you achieve that, anything comes easy.
In fact, that was the only thing in my mind when I replied in previous post.
Most of the time, people react reverse(?) when you try to implement something new. There are several causes for that but the main causes are:
1. A new system means change: change in the positions, change in the work done, change in the responsibilities... "People fed by the existing system doesnot let the system change." I always take this into account.
2. Human is a rebellious creature. You must let people to feel that the system belongs to them. In other case, you must convince or achieve people that you are doing the right thing and the only thing to be obeyed is what you do or say.
3. On the other hand, people are really easy going. If you convict others that you are the only one to be listened or obeyed to, then they willnot even move their finger without you saying them to do.
So... It is a very thin line to implement and sustain a "working" quality system. That's why I say to implement separate systems within each site and HQ with 4 QMRs and a QMS coordinator. Yes, there are identical documents, processes, but different people will apply those!
If you want to discuss more, send me a message with your questions/problems, I will be returning a reply soon.