Thirty years in IT, 28 not as a consultant.
If you work in IT at a typical company, you may have had some good ideas, some recommendations, but they were not given their due by management, and you wondered what it would take to make some meaningful change... then an outside consultant comes in, and says basically the same thing, and management pays attention and says "that's great, let's do that!", and you sit there saying "but that's what I said...", or you keep your peace and help to make the change.
That's just the way things go sometimes, I have no great insight to offer you on this. Management laid out large amounts of money to get the consultant to come in, so it is real hard for them to say "we knew that already" or even "that sounds familiar...".
So, have I been part of something like this since I became a consultant? As Mr Bean said in in his movie "...not that I am aware of." I would like to think I would recognize it when I meet those employees, and try to work with them to increase the chances of success. So far, I have met people who agree on what the problem is I have come on to address, and want to help, but have not seen a case where someone already had figured out the solution before and had been ignored. The thing is, that could actually be true but I may never know it. So, I can only do the best job I can and leave everyone as happy as I can make them.
And if you are are an employee with good ideas not getting their due, maybe its time to start consulting!