Us folks in NPD have very little interaction with it. When we ready a product for launch, we get all of the specifications, DFMEA, testing reports, design controls, etc at the ready and hand them off to a different group who actually inputs them into the PLM through an ECO. Those then get routed to get signoff by marketing, engineering, RA/QA, legal, regulatory affairs, etc. As soon as that becomes "baked", any changes are handled by everyone other than NPD (cost improvements, manufacturing process change, software, testing, etc). If NPD does want to make a change, again, we get the materials ready and they get inputted as a DCO. And again you need the proper signoffs before they can be released.
The signoff process is usually the most frustrating. Want to make a change to the the packing, label artwork? Or the IFU? We need about 20 signoffs. I'm not shitting you. If a comma is out of place, and expect that on your first submission, your DCO will get rejected and you get to go through the signoff up to that point again. It's especially awesome when the 20th signature rejects the DCO.
I should mention that we are a medical device company and our documentation process is more rigorous than most. We are also mostly class 1 exempt devices with a few class 2 and drugs thrown in there. And the FDA and the EU requirements for class 1 are less than class 2. Unfortunately for us, we were acquired by a company that lives in the class 2 and class 3 world. They want us to complete the class 2 requirements for class 1 devices. That is currently an ongoing negotiation where it does not look good for those who believe in less paperwork.
If I were to estimate, figure a day to get the launch package submitted as an ECO. Your signoffs will depend on the structure you create. Ours can take 1-4 weeks, depending on how hard you birddog the process. A DCO or ACR takes minutes to a couple of hours, depending on complexity to create. Signoffs can be quicker, but that depends again on who is needed to sign. You really need to manage the signoffs. Less is better than more. Don't let politics drive who is on the list, it will doom your software to failure.