There seems to be a fundamental difference between the words ‘kaizen’ and ‘kaikaku’. While ‘kaizen’ is used for small changes, ‘kaikaku’ refers to a major overhaul of the entire process.
But, Toyota understands the two terms differently. It practices to undergo many small changes, for one big change. An example that Toyota set, is when it introduced the Prius. It diligently followed the concept of Plan-Do-Check-Act (PDCA), and came up with the first generation of Prius. Many small changes were required to launch a hybrid version that was suitable for the 21st century, and then a lot more for the subsequent models. Toyota understood that for a major breakthrough, a great deal of kaizen was needed.
Kaikaku, on the other hand, is about introducing a lot of changes at a time. This is disruptive, and difficult for the local people to get used to. The disturbance then leads to an unstable system, and to manage it, the people resort back to the older, not so profitable means.
Thus, a good tactic would be to plan a major revolution, and then break it down into smaller, more achievable components. Next, introducing pilot projects will allow the employees to understand and adapt to the changes, and will then lead to a sustainable, constant improvement in the process flow.