The Relevance Of Takt Time?
Takt Time, or “the drumbeat of production” sets the pace for cycle times so that customer demand is met.
Using an assembly line as an example, the cycle time may be the time to move product to the next station. In an ideal world, the takt time and cycle time would be the same to avoid shortages to the customer, or building inventories. In the real world, it is generally understood that cycle time needs to be slightly less than takt time.
Takt time is calculated as Ta over Td. Where Ta is the net time available to work (taking into account breaks, meetings, etc) per shift and Td is the customer demand (units required per period).
All Lean Projects that I have completed have been transactional (ie – business & support processes outside manufacturing processes) and takt time has been the one metric that I have been constantly asked for. The more that I am asked this, the more I wonder about it’s relevance in transactional lean projects in today’s offices.
How many people in “office” jobs or support roles are dedicated to one task? For example, a payroll administrator works 39 hours per week. Their breaks, etc are known so it is possible to calculate Ta (Time available). We know how many payrolls there are, how many employees there are, so it is possible to calculate Td. From my experiences dealing with several companies I would be confident in saying that Time Available is much greater than Time Demanded. In the modern environment this doesn’t mean that the payroll clerks are taking their time or left with no work to do after they have completed payroll – they now have tasks outside payroll to complete. Receptionists are completing PA or HR tasks, Accounts Payable are completing Inventory tasks, etc.
In a more complicated environment it gets more difficult to calculate Time Available as other tasks take up time. In my own case, to calculate Ta is next to impossible, I have to juggle and prioritize tasks to work through them. My role itself is constantly evolving.
So, now for my transactional lean projects, Ta is not accurate. If I was to estimate a time that can be made available for a task, am I allowing time for errors and rework?
How relevant is the much-loved Takt Time outside manufacturing processes??