iSixSigma

Cycle Time

Definition of Cycle Time:

The customer just called again, wondering if the item they ordered will be on time. Will it? Do your company’s processes make it possible to be on time per the customer’s needs? Tto know that requires understanding how long it takes to produce the product, and that requires knowing your cycle times. 

An overview: What is cycle time?

Cycle time is the actual time spent working on producing an item or providing a service, measured from the start of the first task to the end of the last task. Cycle time includes both value-added time as well as non-value-added time. The key word in the definition is actual, as many companies will use cycle time to describe the expected time spent working on producing the item, and these two times are often not the same. To make things regarding a simply concept even more confusing, people often mistake other time concepts, such as lead time or takt time, for cycle time. 

The mathematical formula behind cycle time is not difficult to understand. Subtract the time the first task was started from the time at the end of the last task.

Cycle Time for single piece flow item = Finish Time – Start Time

For example, if the first step of building a toaster starts at 8:30 a.m., and the completed toaster is packaged and ready to ship at 11:30 a.m., the total cycle time for producing the toaster is three hours. 

Cycle time can also be used for specific portions of the total process, having one cycle time for assembly, a separate cycle time for test, and a final one for packaging. 

If dealing with batches of items, instead of one piece flow, simply take the total parts produced and divide that quantity by the production run time to determine the cycle time per part.

Cycle Time = (Finish Time – Start Time) / Units Produced

Say you’re working on understanding the cycle time for painting the toasters from the earlier example. The toasters are painted by an automatic robot arm that paints four toasters at a time in a wave movement. Afterwards, the toasters are placed in a heating chamber to quick-dry the paint. 

From the beginning of the painting to the completion of the paint drying in the chamber takes 40 minutes, but the cycle time is not 40 minutes since multiple products were worked simultaneously. 

Divide the total parts produced, four, into the production run time, 40, to arrive at an actual cycle time of 10 minutes per part.

3 benefits of attending to cycle time

The formulas are straightforward and easy. The real value is knowing what to do with your cycle time information. 

Improve timeliness

The primary benefit of understanding the cycle times of your product or service is to determine if you can provide them in a timely manner that meets your customer’s needs. Takt time and cycle time are often discussed together — and often confused for one another. Unlike cycle time, takt time is the time that a single product must be produced in order to make your customer goals on time. Therefore, for your company to provide on-time delivery, your system must be set up so that your cycle time is less than your takt time.

Set up your system in an ideal way

Knowing your cycle times allows for the proper setup of your processes. In a manufacturing setting, it allows for the proper setup of the production floor. It is important for understanding how many machines, tools, and personnel are needed. If you find out that your cycle time is currently larger than your takt time, you can make modifications to the line. Adding the right personnel, machinery, and additional tools can decrease the cycle time, eventually getting it under your takt time.

Identify possible system improvements

Cycle time is also used to help identify if there are improvements that can be made to the system. Even if cycle time is less than takt time, changes in the environment may increase the cycle time. Regularly monitoring your cycle times will allow you to identify unexpected cycle time increased due to previously unpredicted changes. Perhaps a shortage of material causes delays, or a machine has unexpected downtime, causing an increase in cycle time. It is key to monitor cycle times to verify that customer demand will be met, as well as to identify possible cost-savings initiatives. In many cases, a process that takes less time may be a less expensive process to manage.

3 cycle time best practices

  • Remember not to confuse takt time with cycle time. Many professionals make this mistake. Companies have been known to state that their processes have a takt time value; they do not. Takt time is a function of customer demand and available time, and for many products, takt time is in constant flux as customer demand changes. A system does not impact takt time; it impacts cycle time.
  • Be wary of automated data collection systems. Garbage in, garbage out. While some systems are quite accurate, many systems cannot be trusted due to poor collection processes. Go out to where the work is accomplished, and perform a time study to gather reliable actual cycle time data. Not only will the times reflect reality, but you are likely to find other issues with your process that need adjustment.
  • Do not think of cycle time as a constant. Too many professionals get stuck on how long the process should take without realizing that while processes are set up to meet a cycle time goal, factors such as supply chain issues, machinery downtime, personnel shortages, etc., will always keep cycle time a variable.

Frequently Asked Questions (FAQ) about cycle time

Should I use the cycle times present in my companies, or should I try to manually track the times?

This is a challenging issue, as few computer systems do a great job of tracking certain times. Overall, most computer data systems do a great job of telling you the overall cycle time for a product but do a poor job of verifying a cycle time for a specific part of the process. This is because many companies have poor tracking regarding when the product leaves one part of the process and enters another. 

These computer systems are also poor in identifying value-added time versus non-value-added time. For anything other than a total system cycle time, it is advised to try and take a handful of manual measurements. Witnessing the process live, versus as data on a computer screen, will always yield more important information.

My individual cycle times for each part of the process seem to be far less than the total overall cycle time for my product. Why?

Remember that when you take the overall process and divide it into parts, you must take into account any inventory wait times between the processes. Often, a company will neglect to measure the wait times between the steps, then see a large discrepancy between the cycle times of each portion of the process versus the total cycle time. These inventories between process parts, especially when production stages occur in different batch sizes, can be significant.

Is cycle time what I want to measure for office environments?

Absolutely! Office environment processes are often hidden and poorly understood. Knowing the overall times of the major steps of the process will help you better understand where possible improvements can be made, and whether you can expect to complete the documents or services that your customer needs. 

In addition, as mentioned in the previous question, the wait times between major sections of the process, or between departments, are often huge amounts of non-value-added inventory time sinks. Overall cycle time increases are often the “canary in the coal mine” when problems arise.

Cycle time is key to reaching on-time delivery goals

Knowing your cycle time allows you to estimate your product delivery time, checking it against takt time to confirm customer demand can be satisfied in an acceptable amount of time. It is used when setting up the process for on-time delivery and is a useful metric when chasing down quality issues and measuring continuous improvement projects. Just remember not to get it confused with all the other different types of time-based metrics, especially Takt Time!  

Remember that business always comes down to keeping your customers happy, and using cycle time to help guarantee on-time delivery is an important key to achieving that goal.

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