I think it is an interesting question. Your answer will most likely make a big difference to the results you achieve . And, to keep it simple, I think there are two main answers (based on my experience of watching what people do):

It's amazing just how much people will put up within a business. The wrong tools, the wrong process, unclear instructions... what can become normal is fascinating. Let me give you an example from the back end of last year.

I was talking to a business the other day that had a good MRP system in place within their very large business. But, they weren't truly using it! They had set up most of the parameters, and the system was certainly working as expected, but they still weren't using it the way they should. They didn't trust it!

Where do you keep your continuous improvement plans? Are they safely stored on your computer's hard drive, in the cloud, or on a wall somewhere? The answer to this question may reflect the rate of completion of your plans.

There is an ongoing fight between 'good' and 'bad' when it comes to business processes. Some people want to do things in the right way, with the right processes, consistently. Some people don't appreciate the need for doing things in the right way consistently. Over time this can make a huge difference to the results we obtain as a business.

We have so many pressures on us at times to improve. Trying to make progress becomes one of the most important things we have to do. There can be so many opportunities too. A myriad of ideas that we could get our teeth into. So, why do many of us get limited results?

There was a really interesting article on the BBC News Magazine website yesterday about continuous improvement and not ignoring the small things that can make a big difference. I agree that there are many small disciplines that a lot of businesses give lip service to that could make a big difference in terms of their performance; developing a productive routine is one way to get around this. The article is definitely worth a read, you can view it here -  http://www.bbc.co.uk/news/magazine-34247629 . Giles Johnston Creator of the ' Making It Happen ' online course for discovering change management strategies.