In my last post, I introduced the concept of takt time. In this post, I’ll discuss how to apply this concept to a couple situations and demonstrate that takt time can be manipulated.
You’ll recall that takt time is the pacemaker for your process (hence why it is derived from the German word taktzeit, meaning “metronome”), and that it is calculated as:
Time Available / Customer Demand (in that period)
Takt time tells us how fast we should work on average in order to meet the incoming demand for our services or products, in order to avoid backlogs, bottlenecks, and delays.
Example 1: Department of Excise and License
The Department of Excise and License has four licensing technicians to help individuals and businesses receive their liquor, taxi cab, merchant guard, and other licenses. On average, they get about 88 people coming in each day, and are open for 8 hours (taking two, 20-minute breaks during this time). Here’s our takt time calculation for this example:
Time Available to Work = (8 hours * 60 minutes/hour) – 40 minutes for breaks = 440 minutes
Customer Demand = 88 licenses
Takt Time = Time Available to Work / Customer Demand = 440 minutes / 88 licenses = 5 minutes per license
Assuming each license takes 20 minutes to process, are they meeting their takt time? The answer is yes! Recall that the department has 4 licensing technicians, each taking 20 minutes per license. So, 20 minutes / 4 licensing technicians = 5 minutes per license; therefore, they are meeting takt time on average.
Example 2: Construction of a Hydroelectric Plant
Using takt time for a major construction project isn’t useful if the plan is to complete one project in four years. In that instance, all we would see is a clock counting down from that four year mark, which is not helpful. Instead, we break up the project into component parts so that takt time becomes a guide for pacing the work.
For this example, we need to pour 111,370 cubic yards of concrete in 50 days (our customer demand, or in this case, our project’s demand). So, we have 50 days to get this done, but we need to factor in lunch and breaks in order to determine how much time we have available to work. Our time available to work = 50 days * (8hr working day – 1hr lunch & breaks) * 60 mins/hr * 60 secs/min = 1,260,000 seconds. This means that in order to finish this part of the project on time, we need to pour one cubic yard every 11.3 seconds (1,260,000 / 111,370).
Depending on the task at hand, we may be able to manipulate the takt time equation to provide some breathing room for our work processes. If our customer demand is not dependent on the time available to work, and is therefore constant, we can increase our time available to work to increase the takt time we need to reach. Similarly, if time available to work is the same, but we can find a way to reduce the customer demand, we can also increase our takt time.
Let’s go back to the example of the hydroelectric plant being built. Our takt time for pouring the concrete is one cubic yard every 11.3 seconds, but if our machines can only pour as fast as one cubic yard every 12.5 seconds, we have an issue. Therefore, we may need to either redesign the project so less concrete is needed (reduce demand), contract out a portion of the pouring (reduce demand), or work longer days (increase time available) so that the project isn’t delayed. Reality is, each of these options comes with an additional cost, so there’s a tradeoff to this approach for meeting takt time.
In short, if we’re struggling to meet takt time, one option is to rethink the problem at hand and increase the time available and/or decrease customer demand. However, takt time should be a tool or a guide for your process, and not something to fiddle with to make more convenient. A more sustainable strategy is to streamline your process to more easily meet takt time, which I’ll talk more on in my next post.