By August 25, 2009 6 Comments Read More →

Two Types of Cycle Time = Confusing

This blog post started as a parenthetical comment about cycle time in my last blog post from this morning. But the parenthetical grew out of control and I thought it would only confuse things in that post.

So, hopefully, it’s more clear here as a standalone post. In the last post, I explained that “cycle time” meant:

“Cycle time” is a term that means how long it takes to do a repetitive job each time.

Unfortunately “cycle time” is also used to mean how long it takes to get through an entire process from start to finish. This is confusing, I know. As an Industrial Engineer, I’ll take lumps on behalf of my profession for this poorly chosen terminology (are we to blame?). Some prefer to call this second form of cycle time (end-to-end elapsed time) by an alternative phrase “throughput time” or many in healthcare would call this “turnaround time.”

But the “cycle time” I mean here is the time between a single person (or machine) starting the first piece of work and that person (or machine) starting the second piece of work. Some would call this “operation time” or some other term.

If a doctor, for example, sees six patients per hour, the doctor’s cycle time is 10 minutes per patient. If it takes the patient 60 minutes from arrival to departure, then the “turnaround time” is 60 minutes (see why we don’t want to also call that”cycle
time?”)

I wish we didn’t have this confusing terminology, where “cycle time” means two things. I’m always havin to ask for clarification about “which” cycle time a person means (although “throughput time” is normally MUCH longer than “cycle time” for an individual operation in a process).

How do address that in your workplace?

Subscribe via RSS | Lean Blog Main Page | Podcast | Twitter @MarkGraban

Please check out my main blog page at www.leanblog.org

The RSS feed content you are reading is copyrighted by the author, Mark Graban.

, , , on the author’s copyright.


Thanks for reading! I’d love to hear your thoughts. Please scroll down to post a comment. Click here to receive posts via email.


Now Available – The updated, expanded, and revised 3rd Edition of Mark Graban’s Shingo Research Award-Winning Book Lean Hospitals: Improving Quality, Patient Safety, and Employee Engagement. You can buy the book today, including signed copies from the author.

Related Posts Plugin for WordPress, Blogger...
Please consider leaving a comment or sharing this post via social media.

Mark Graban's passion is creating a better, safer, more cost effective healthcare system for patients and better workplaces for all. Mark is a consultant, author, and speaker in the "Lean healthcare" methodology. He is author of the Shingo Award-winning books Lean Hospitals and Healthcare Kaizen, as well as The Executive Guide to Healthcare Kaizen. His most recent project is an eBook titled Practicing Lean that benefits the Louise H. Batz Patient Safety Foundation, where Mark is a board member. Mark is also the VP of Improvement & Innovation Services for the technology company KaiNexus.

Posted in: Blog

6 Comments on "Two Types of Cycle Time = Confusing"

Trackback | Comments RSS Feed

  1. Larry Loucka says:

    My first experience with cycle time was when working at a multistage stamping press and marking a section of the metal strip and following it through the successive stages of the deep draw. The time from flat metal strip to finished piece was cycle time. The number of pieces per minute was the "piece rate". But then others will stand at the end of a process and take the time between two successive pieces and call that cycle time.

    APICS Dictionary defines Cycle Time as: 1) In industrial engineering, the time between completion of two discrete units of production. For example, the cycle time of motors assembled at a rate of 120 per hour would be 30 seconds. 2) In materials management, it refers to the length of time from when material enters a production facility until it exits. Syn: throughput time.

    Oh well…

  2. Mark Graban says:

    Larry — even though I don't encourage blaming, I'll blame APICS then, not industrial engineers :-)

  3. Russell says:

    A related cadence is Takt time – the rhythm of the process as a whole: http://en.wikipedia.org/wiki/Takt_time

  4. Laura Cibulsky says:

    My experience is that we have had to make sure perspective is clear when we talk about "time". When we are discussing takt time we typically use the phrase "rate of demand" or just "demand" indicating customer perspective at the end of the line.
    When we are talking from the product or service point of view we usually say cycle time (start to end of a single "cycle" usually one processing step). It does get confusing if the perspective is not clear.
    I believe in Shook's "Learning to See" he uses "lead time" to describe "turnaround time". That term (lead) works for me because I think – "How much time do we need to leave in the schedule to get the material (i.e. patient) through the whole process (appointment)."

  5. Mark Graban says:

    I prefer using "throughput time" for internal factory elapsed time from start to finish, where I use "lead time" for how long it takes to get something from a supplier (or to a customer) including transportation time.

    We could do a whole other blog post on how people misuse "takt" to mean production rate instead of demand rate.

    Maybe "production rate" and "demand rate" are the best terms to use? Except for hospitals, we need a different term than "production"!!

  6. Bruce Baker says:

    Although I usually blame APICs for eveything bad (just kidding I don't think we should blame either – although I do get frustrated with my inability to help some APICs certicatees see beyond MRP and square roots of lead times, etc.) I usually use the APICs definition listed above as my definition of cycle time and then I compare that to TAKT and try to get cycle time to just below TAKT time. I usually call the time from beginning work on a piece or patient to finishing that piece or patient throughput time or process time.

Post a Comment

CommentLuv badge