Takt time

When designing a work cell, you need two key pieces of information—the customer demand rate and the time the process takes. With this data, you can determine takt time—the rate at which you must produce in order to keep up with demand. 

Once you have the customer demand rate (DR) for your product or service, and the cycle time (CT), you can determine the number of resources (NR) needed to maintain takt time by using two simple formulas ... 

For example, RayRay s research shows that the demand rate for hair cuts is one customer every hve minutes (DR = 1/5, so the takt time is 5 minutes). The cycle time for a hair cut (not including check-in, shampoo, or payment) is 15 minutes [NR = (1/5)(15) = 3]. So, RayRay s would need three resources, or stylists, to maintain takt time and keep up with customer demand. 

Ifthe process requires more than one person to maintain takt time, you can apply workload balancing to create an even distribution of work across the resources so that none are overburdened or underutilized. For more information about workload balancing, see The Toyota Way Fieldbook, by J. Liker and D. Meier, New York McGraw-Hill, 2005. 

When you re ready to put everything into place, conduct a test run of the work cell design and all the associated processes to make sure you can meet takt time and that everything goes as planned. 

Using this kind of mixed model sequencing, the hne balance can be kept close to 100 percent even though the standard time or cycle time varies for each product. For example, suppose that the line s takt time (cycle time to meet demand) is two minutes and the respective standard times of products A, B, and C are two minutes, three minutes, and one minute for a certain process. Then the cycle time for the A B A C sequence is balanced and equal to eight minutes. The individual time differences between products in the sequence can be accommodated by utilizing a space buffer between adjacent processes. 

Minimizing work-in-process inventory is a goal of JIT. In keeping with this, the number of units per standard container should be kept as small as possible, with one being the ideal. Furthermore, the number of deliveries per day (p d) should be set as frequently as possible so as to synchronize with the takt time of the subsequent process, and the delivery delay factor c should be kept as short as possible. Ideally, the number of kanbans in circulation between two adjacent workstations also should be minimized. However, in consideration of practical constraints, a tentative number of kanbans may be calculated as follows ... 

Machine loading, system balancing, and takt time... 

Strategic Pull can be defined as establishing a takt time to set the output of the production plant to be equal to demand. 

Drumbeat The pace at which an organization produces product. Used to pace all the operations in a factory or in a supply chain. Similar to takt time. 

Conceived of as five days and one night applying Toyota Production System principles that includes process observation, cycle time calculation, calculation of takt time, calculation of value-added ratios, elimination of work, and preparation of standard worksheets. 

Level plant loading Efforts to reduce variability in production at the business unit and supply chain levels. Level plant loading is considered a best practice for achieving effective supply chains. Drumbeat and takt time are related terms. 

Takt time The interval that sets the pace of production to match the rate of customer demand. It is the heartbeat of the lean production system. The term is derived from the German expression for a metronome beat. (Adapted from APICS Dictionary, lOtb edition )... 

Takt Time is the pace of production needed to meet customer demand. It is the average rate at which customers buy products and hence the rate at which products should be manufactured. It is expressed in time units -one every so many minutes or so many minutes between completions ... 

Value Stream Mapping (VSM) Key Performance Indicators (KPI) Takt time Lead time... 

At this point, we are ready to calculate TAKT time. TAKT time is the time it will take to produce one unit of product in order to meet customer demand. It is calculated by dividing the Available Time by the Customer Demand (over that period of time). Looking at Chart 8.3, we see the TAKT time calculated for this example. Assuming a 7.5-hour workday, we get 27,000 sec per day. Then, in order to produce 16 pumps each day, we would need to complete a pump every 1,688 sec or 28.1 min. 

Balanced Production All operations or cells produce at the same cycle time. In a balanced system, the cell cycle time is less than TAKT time. Batch-and-Queue Producing more than one piece of an item and then moving those items forward to the next operation before they are all actually needed there. Thus, items need to wait in a queue. 

Standard Work A precise description of each work activity specifying cycle time, TAKT time, work sequence of specific tasks, and minimum inventory of parts on hand needed to conduct the activity. 

TAKT Time The available production time divided by the rate of customer demand. For example, if customers demand 240 widgets per day and the factory... 

Operates 480 minutes per day, TAKT time is two minutes if customers want two new products designed per month, TAKT time is two weeks. TAKT time sets the pace of production to match the rate of customer demand and becomes the heartbeat of any Lean system. 

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