Measuring Kanban
Two commonly cited methods of measuring the performance of a manufacturing process are flow through time and work in progress inventory levels.
Flow through time is takes once unit to pass through the entire process from start to finish ( on average) . in the kanban system both of these measures are at least partially dependent upon lot sizes.
For example if a kanban system uses 25 workstations and a lot size of 54th the average WIP will be near 100 units. If the cycle time for a balanced load is say two minutes per item ( using the lot size of 4 ) . flow through time will be close to 200 minutes (allowing for some variation) : one unit of product will flow through the system in 200 minutes.