Kaizen - Small continual improvements
Kaikaku - Idea that can cause a radical change
Kakushin - Ideas that cause revolutionary transformation
Example: - Lets consider a grocery store (Brick and Mortar)
When the Grocery store implements a barcode system for tracking the Stocks, its a small improvement that automates the manual effort of Stock keeping and is a Kaizen.
When the store deploys robots for managing the store, it’s a radical change where the store doesn’t rely on human resource for managing the store and is a Kaikaku.
When the Store evolves from a brick and mortar store to an online e-commerce business, its a revolutionary transformation and is a Kakushin.