You can improve process flow in a number of ways using Lean Six Sigma, including by reducing waste. The seven categories of waste are sometimes identified by the acronym Tim Wood:
Transportation: Moving materials and output unnecessarily.
Inventory: Overproduction resulting in too much work in progress or stock.
Motion: Inappropriate siting of teams or equipment.
Waiting: Equipment failure, for example, which causes delays.
Overprocessing: Performing unnecessary processing steps.
Overproduction: Producing more stock or producing it earlier than needed.
Defects: Dealing with rework.