Probably among the most popular leveling approaches is Every Part Every Interval (EPEI). Often, this is the method people mean when they talk about leveling (also known as heijunka [平準化]).
The theory about this type of leveling is not very difficult. Unfortunately, hard facts of reality often nullify any possible advantage of this type of leveling. In fact, most of these types of leveling that I have seen were complete rubbish. They were a dog-and-pony-show to please management at the expense of performance and shop floor efficiency. In this post I will explain to you how it is supposed to work in theory. In the next post I will explain why it rarely works in practice .