A Better Way To Work TimeBack Management

About Dan Markovitz

Dan Markovitz is the founder and president of TimeBack Management. Prior to founding his own firm, Mr. Markovitz held management positions at Sierra Designs, Adidas, CNET and Asics Tiger. Learn More...

Leveling; smoothing out the flow; e.g., doing two performance evaluations a day for 3 weeks, rather than ten a day for three days -- and then needing to take a vacation because you're so burned out.
Overburdening people, process, or equipment; e.g., people working 100 hour weeks for months on end -- come to think of it, like most lawyers and accountants.
Uneveness or variability; e.g., leaving work at the normal time on Thursday, but having to stay at the office till midnight on Friday because the boss finally got around to giving you that project...at 4:30pm.
Waste; activities that your customer doesn't value and doesn't want to pay for; e.g., billing your customer for the really expensive 10am FedEx delivery because you didn't finish the document on time.

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Batching is not (necessarily) a dirty word.

Posted October 20, 2008 @ 5:11 PM

One-piece flow (or single-piece flow) is one of the core concepts of lean manufacturing.  The idea is that we should produce one item at a time, when the customer needs it. This concept stands in opposition to batch-and-queue production, in which we make a whole bunch of one thing, then make a bunch of the next thing, etc. A lean car factory might make one green Corolla, then one blue Camry, then one red Yaris, for example, while a mass production factory would make 100 black Wranglers, then 100 purple Cherokees. For many reasons, it's way more efficient to run the factory the first way rather than the second.

But while batch-and-queue production isn't the best way to run a factory, in many respects it is the best way for you to work. Why? Because unlike the single-task machines on a production line, you perform many types of operations: talking on the phone, writing emails, building spreadsheets, reviewing proposals, solving a problem with one of your colleagues, dunking Krispy Kremes in your latte, etc. The need (and ability) to do so many types of things makes you a "monument machine."

Monument machines are fantastically complex, terrifically expensive, and perform an amazing variety of tasks. (There. I've used up my superlatives for the week.) Manufacturing engineers love them, because they're so cool. Lean adherents hate them because they necessarily require non-productive changeover time when they're switched from one task to the next. Lean companies are always looking for ways to get rid of them and replace them with simple, single-task machines. But when they can't be eliminated, it's most efficient to do batch production: first paint all the red cars, then all the green cars, then all the black cars, for example.

Just like a monument machine, there's non-productive changeover time when you switch from one task to the next. When you stop working on a spreadsheet to answer an email, it takes your brain a little while to transition to the processes required for the new work.  David Meyer, a psychologist at the Federal Aviation Administration, explains that

In effect you've got writer's block briefly as you go from one task to another. You've got to (a) want to switch tasks, you've got to (b) make the switch and then you've got to (c) get warmed back up on what you're doing.

While your brain is pretty damn fast at this transition, there is a real time cost.  Meyer says that

People in a work setting who are banging away on word processors at the same time they have to answer phones and talk to their co-workers or bosses -- they're doing switches all the time. Not being able to concentrate for, say, tens of minutes at a time, may mean it's costing a company as much as 20 to 40 percent in terms of potential efficiency lost, or the "time cost" of switching, as these researchers call it.
And there you have it: pure muda. Pure waste.

My prescription for reducing this waste is to batch process your various types of work.  If you need to have 1:1 meetings with people, do them in one batch. If you have to work on spreadsheets or write code, do that in one batch. Whatever you do, don't interrupt these tasks by checking email. Instead, batch process your email a few times per day. I promise you won't miss much: if there's something really important, the sender will find you. Really. (But do them (and yourself) a favor  -- let them know in advance that you're going to a new mode of email processing.)

One of my clients doesn't allow me to use the word "batch" when I teach their staff, because it doesn't fit with lean principles. They prefer the vaguer, more euphemistic injunction to "group similar types of work." But I believe that batching isn't a dirty word when it reduces the waste in a process. And when you're dealing with human monument machines, it most certainly does.

But let's talk about people


Thanks for the thoughtful comment. I agree with you in principle re: the paint shop. However, I'm mostly concerned with the effect of batching vs. single piece flow as it affects knowledge work. And in this case, I think batching is better.

I disagree

I disagree. Single piece creates stability, Stability helps to make abnormalities visible, such as "a painting process that is painful to wash the previous color thoroughly, when changing to the next color on the painting nozzle of the robot". Now what you do with that makes all the difference. You can either batch and always (ignorantly) have that problem, or you can single piece and put pressure on it and fix it through kaizen. "Ignorance is bliss" but not when you strive to continually improve.
And as for cost v.s. benefit analysis - You can either deal with the long term cost of ignoring the problem, or fix it with the short term cost of improvement.

Batching is not a dirty word

I am totally agree with you on this, whatever you are going to batch One-piece flow (or single-piece flow) the idea is that we need to make product when a customer demand. but this thing can change the atmosphere.

Batching is not a dirty word

I totally agree with you on this. Whether to batch or go with single piece flow depends on the resources that is wasted (set up or change over is a muda -does not add value to customer) vs the value derived (for example quick turnaround time, consistent quality levels etc)

In the car example you are quoting, change over in a painting process is painful to wash away the previous color thoroughly to change to the next color on the painting nozzle of the robot etc and hence companies specifically use the grouping technique (through sequencing) for optimum throughput. However, in final assembly they could go for single piece flow as the wastages in changeover is very less compared to the benefits.

So, I would say whether to batch it or not solely depends on the Cost Vs Benefit analysis of batching vs single piece flow!!

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