Takt time is much more than a simple metric or calculation. To understand why, let’s explore four different ways that takt time can impact your manufacturing process.
|Area of Impact||How Takt Time Helps|
|Capacity Planning||Understand and quantify differences between customer needs (takt time) and manufacturing capabilities (operable takt time).|
|Process Design||Ensure you meet customer demand in the medium to long term by changing operable takt time through changes to your process and/or equipment.|
|Production Scheduling||Ensure you meet customer demand in the short to medium term by changing available production time through changes to shift schedules and/or process staffing.|
|Plant Floor Operations||Establish a real-time production target based on operable takt time that enables your plant floor team to “win the shift.”|
Capacity planning helps you determine how much production capacity you will need to meet customer demand. You can think of it as comparing:
Any discrepancy between the two will lead to a suboptimal result, which can be either:
Therefore, the goal of capacity planning is to strategize the best way to align takt time (driven by demand) with operable takt time (driven by your manufacturing process). The associated time horizon is typically medium to long (months to years), since in order to accurately calculate takt time, you need a clear understanding of demand over time and how much demand you intend to meet now and in the future.
Once customer demand is forecast (and thus fixed), there are two strategies to bring takt time and operable takt time into alignment:
Process design establishes your operable takt time, which is the pace you can actually achieve on a sustained basis with your current process and equipment.
There are very interesting parallels between ideal cycle time and operable takt time when thinking about the throughput of your process.
Keep in mind that it is nearly impossible for processes to run continuously and perfectly. Doing so would represent 100% performance (every cycle as fast as possible), 100% availability (always running with no downtime), and 100% quality (no defects). Therefore, it is important to budget losses into your operable takt time so you have an accurate picture of real-world capacity and throughput.
Production scheduling enables you to adjust takt time to better meet customer demand in the short to medium term by changing available production time (referred to as planned run time from a manufacturing perspective) either:
Since customer demand is usually treated as fixed, the only “lever” you have to pull in changing takt time is planned run time.
In order to accommodate fluctuations in demand, schedule:
The plant floor is where takt time is transformed from concept to practice. It is where the rhythm of production is executed. In lean manufacturing terms, it is the place of “gemba” (the actual spot or scene).
There are important nuances to consider when applying takt time to the plant floor.
The first is whether takt time should be interpreted as a strict pace that is not be exceeded. For the vast majority of manufacturers, the answer is no. Unless you need to constrain pace due to design constraints, such as to control defects, operable takt time should be considered an improvable metric. You want your operators to have an opportunity and incentive to improve. Production time that is recovered can be used for other productive activities, including process improvement and production of other parts.
The second is how to translate takt time into something concrete for operators. There is a valuable opportunity here, which is using operable takt time to drive real-time targets so operators know exactly how they are performing against expectations.
Rather than using a whiteboard or a simple pace timer, which is more or less the equivalent of a repeating stopwatch, we recommend a scoreboard with TAED: Target, Actual, Efficiency, Downtime. The beauty of TAED is that it transforms takt time into an opportunity for operators to “win the shift.” It motivates and informs your operators by enabling them to see exactly where they stand in real time. Target is a dynamic value that lets operators know where they should be right now. Unlike a static goal, the target value is always relevant.
More specifically, a TAED scoreboard displays the following real-time metrics:
|Target Count||A target for good parts driven by operable takt time. Each time the operable takt time is reached, the target count increases.|
|Actual Count||The actual number of good parts completed.|
|Efficiency||Calculated as actual count divided by target count. 100% or higher means your team is “winning the shift.”|
|Downtime||Included as it is by far the largest source of lost time for most manufacturers. It’s good for operators to keep eyes on this metric.|
And speaking of downtime - much like how an Andon uses a visual indicator to highlight instances of downtime, the TAED scoreboard should also highlight down events and prompt the operator to select a reason or use integration tools to retrieve that information automatically.
Many companies see an immediate improvement in productivity simply by setting a challenging but attainable target (via operable takt time) and showing operators the status of production in real time.