One question facing a company wanting to improve manufacturing performance is whether to implement improvement initiatives in parallel or sequentially. This article examines whether any sequences of manufacturing improvement initiatives exist and what these sequences are. For two and a half years, the author participated in and studied one company's implementation of lean production. The findings group the principles of lean production into four different categories, depending on when management devoted effort and resources to the principles. The conclusions indicate that there are sequences in which lean production principles are implemented, but management also need to devote effort and resources to a set of principles in parallel.