Takt Time, Cycle Time, Lead Time

hello welcome to this operational excellence video today we will be learning about tack time cycle time and lead time we'll examine the three different times and explain how they are related and how they differ knowing what these terms mean and how and when they apply we'll help you understand and design your processes to better meet your customers demands first of all let's look at tack time tack time is a calculated value that describes the theoretical demand rate of your customer in other words it is the rate at which you need to produce in order to meet their demand tack time is calculated by dividing your available production time by the number of units your customer needs so for a single shift operation running seven and a half hours a day 20 days a month you have a hundred and fifty available hours or five hundred and forty thousand seconds if the customer needs twenty thousand units the calculated tack time is 27 seconds so in order to meet the customer demand one unit will need to be produced every 27 seconds at a minimum tack time is useful to get a gauge on what is actually needed in order to meet your customers demand but it would not be wise to run it exactly 27 seconds unless you know your process never has an issue most operations know there are going to be issues especially early in the learning curve as a result they plan to run faster than their tack time by a certain increment to allow for some downtime this would be their targeted cycle time cycle time is the rate at which your operation is actually producing a unit cycle time is measured as the frequency of units produced so if you are watching a process the cycle time is the time it takes from the output of one unit to the output of the next unit you can continue to measure those cycles output output output etc to determine how reliably your process is able to meet its cycle time producing at a consistent and predictable cycle time indicates a stable process and allows you to see abnormalities quickly lead time is the measurement of how long it takes one unit to make its way through your operation front to end you measure the lead time by watching a unit enter the operation following it through the entire process and stopping when it leaves the last step lead time is a useful measurement in two ways first if your product is a made-to-order product it tells you how long your customer has to wait for their unit to be completed secondly it can be a gauge on how much inventory is in your process it only takes five minutes worth of effort to produce a product but the lead time is five days that means your operation has a lot of inventory between every step delaying the output of the work value stream mapping can help highlight where those inventories are located to understand tack time cycle time and lead time further let's look at a scenario and apply the terms as we go in this scenario we have a small company that produces colored circles on white paper the operation requires three work steps tracing cutting and adhering step 1 tracing outlines the circle to be cut step 2 cutting cuts the circle step 3 adhering attaches the circle to a sheet of paper the company has three employees one on each step currently the company has one customer that regularly orders 36,000 units a month if the company ran a seven and a half hour shift per day what would the tech time be let's review the tactical collation again tack time is the calculated demand rate available time divided by units needed the available time in a seven and a half hour shift is 27,000 seconds multiply that times twenty days in a month equals 540 thousand seconds in the month so are available production time in the month is 540 thousand seconds in this scenario to get tack time we need to divide 540 thousand seconds by the number of units ordered or in this case thirty-six thousand when we do that we get the TAC time of 15 seconds per unit this company will need to produce one unit every 15 seconds during their seven and a half hour shift to meet their customers demand now let's watch the process to see how we do let's measure the cycle time of the operation to do that we simply have to measure how frequently one unit comes off the end of the line let's measure output output I'll put when we measure the cycle time we get roughly 13 seconds do these times meet our tack time yes they do if we continue to run at this pace we will meet our customer's demands now let's evaluate the cycle times of the individual processed apps with enough inventory to let them run let's watch the output of tracing output output output now let's watch cutting I'll put output output and Leslie adhearing output output output the cycle time of tracing is six seconds the cycle time of cutting is 13 seconds and the cycle time of adhering is 6 seconds after examining the individual times it is clear that the output of cutting is far slower than the other two steps while was our tack time again correct 15 seconds even though cutting is slower it is still meeting our tack time so as a whole the process is meeting tack time looking at the timings of each step are there ways to improve this process sure the first and last step could be combined and still meet tack time another option would be to have two cutters which could bring the overall process cycled I'm down to six seconds in this scenario the additional speed is not required so the first option might be preferable here we have our combined self the first operator is tracing handing it to the second operator for cutting and then adhering the previous circle this balance is the work content between the two operators now let's change the scenario a little bit because the company improved the process and reduced its cost another customer has decided to order some units this customer requires 36,000 units a month as well but we'll need their units completed in 30 seconds to serve their customers so from the time they put in an order they need to receive that unit within 30 seconds because we have more volume now we need to recalculate our TAC time once again TAC time is the available time divided by units needed the company's available ship time is still 540 thousand seconds a month the number of units needed is now 72,000 36,000 from each customer so our new TAC time is 7.5 seconds per unit remember the improvement options we had in the first option we can combine the first and last step and end up with a 13 second cycle time and the second option we could add a second cutter and end up with a 6.5 second cycle time another option could be to combine the first and last step and run to cells to still end up with a 6.5 second cycle time another option would be to run two shifts of the combined cell increasing the available work time the cost of equipment and the space it requires might dictate which of the options we select but running two cells would give us more staffing flexibility so let's select that option now we have two cells running with tracing and adhering done by the same operator let's measure the output cycle time of each cell starting with the cell on the right output of the cell output of the cell output of the cell this cell is producing at 13 seconds unit now let's look at the one on the Left output of the cell output of the cell output of the cell this cell is producing at 13 seconds as well with two cells producing a unit every 13 seconds we effectively have a unit coming out of our operation every 6.5 seconds which meets our TAC time of 7.5 seconds now let's measure the product lead time if customer to orders a unit will they get it in 30 seconds to measure this we'll select a color to follow through the process we'll select green as step 1 grabs a green sheet we'll start the clock now we watch it as it goes through the entire process tracing cutting adhering when adhering is done and puts it into the completed pile we stopped the clock in this case our lead time was 21 seconds because our customer needs these orders within 30 seconds a 21 second lead time will be sufficient if our lead time was greater than 30 seconds we could Valley Stream out the process to look for ways to eliminate inventory we have looked at two different scenarios calculated tack time with different volumes measured cycle time to see if we are meeting our tack time and measured lead time to see if we are meeting our customers SLA now that you understand how to measure your process with tack time cycle time and lead time why don't you go and measure your own process you might be surprised at what you find you you

Channel: OpsExcellence

Views: 539,032

Keywords: Takt Time, Cycle Time, Lead Time, Lean Manufacturing (Literature Subject)

Id: isu6MG3v0-s

Length: 13min 49sec (829 seconds)

Published: Tue Feb 10 2015