When you are changing a process you need to get 'buy in' from the people who are key to operating the process.
What do you do when everyone is 'too busy'?
When you are changing a process there are usually a handful of key points that need to change. Taking the time to spell these changes out to your colleagues is time well invested.
Many times I have seen businesses try to make changes happen, people agree to the changes and then nothing happens. The same way of working continues, there isn't even a temporary change as people try out the new way of working.
They didn't understand the change taking place, but weren't offended by it either.
When you have a conversation with them about the specifics of the change that is often the time when the penny drops. Don't just issue them with a document, tell them about what has changed, why it has changed and what they need to do.
It can take a little longer to get around the key people, but the results speak for themselves.
...optimising MRP systems and re-engineering business processes