Takt Time and Leveling - What’s The Point?

A few days ago I wrote about asking “What is your takt time?” and the likely responses to that question. But in my list of common responses, I left one out - “What’s the point? We get everything out by the time the truck leaves.”

Here’s a real-life example: In a high-volume consumer goods factory we had a daily transportation cycle. Shipments left once a day. Parts and materials arrived once a day. Although the operation was not without its glitches, the process itself incorporated a lot of automation (another story entirely), and the time through the machinery was pretty quick.

We were trying to implement the production leveling (heijunka) into the enterprise flow between the factory and the distribution system. While the mechanics were very straight forward, leveling the model mix during the course of the day encountered a logical question: What’s the point?

And what is the point? With or without model-mix leveling the same stuff ended up on the truck at the end of the day, and the total amount of inventory in the factory was not going to dramatically change. So why go through the trouble, especially of working changeovers on the packaging equipment, when there was apparent no net effect?

The question is a logical one until we understand that takt time (or pitch in this case) is not a production quota. It is part of a standard.

What’s so important about standards?
Without a standard, you can’t detect a problem.

Daily management is about rapidly detecting, correcting and solving problems. This is much easier to do when dealing with small problems before they grow into big ones.

The “What’s the point?” question even gets asked in the course of many lean manufacturing implementations. The operation reaches a level of performance that is “good enough” - for example, everything makes it onto the truck by the end of the day - and they are satisfied with that level of performance. This is when continuous improvement stops.

Have all of the problems been solved? Has all of the waste been removed? Of course not. But the next level of problems, and therefore the next level of performance, is under the radar.

In the factory I described above had more demand than they could handle. They were already working 24/7, and were working to add capacity. They wanted to speed up the automation, and possibly even add additional lines. Yet, during the course of a day:

• They lost many units to defects.
• The lost production to machine stoppages and slow-downs.
• They had part shortages and frequently substituted one product for another in the shipments, and made it up tomorrow.
• Because they were “behind” they relentlessly kept the lines running, only to find defective product in final inspection.

The list goes on. They are all familiar things.

So what is the point of applying leveling product mix and establishing the discipline of a takt time or pitch?

Honestly, there isn’t any point unless they also implement a leadership process to immediately call out and respond to any slippage or deviation from the intended pace and sequence of production.

So - what started out as a question about a common tool or technique in the TPS has come around to what the core issue really is when that “What’s the point?” question is asked: Lean manufacturing is not about the tools and techniques. It is a system to assist a proactive leadership culture that is almost obsessed with finding and fixing the problems that keep them from achieving perfect safety, perfect quality, perfect flow, with zero waste.

A “problem” is any deviation from the standard. (And if you don’t have a standard, that is a problem.)

Two key questions:

Are we meeting the standard? If the answer is “yes” then:

Are we looking at perfection?

One or the other of those questions is going to drive you to address the next level of problems.

Training - Critical Questions To Ask

There is lots of “Lean Training” out there, and the quality ranges across the board.

“Lean training” is a megabucks business, and anyone who can assemble a pack of PowerPoint slides and a web site is offering “lean training” out there. It is certainly a case for buyer-beware. So how do you evaluate all of the alternatives, especially if you are just learning and might not be in a position to judge? (Irony: If you are in a position to critically judge these training programs, you probably don’t need them.)

What is being taught and how?
In my experience, most people will readily agree that the tools and artifacts usually associated with the Toyota Production System or Lean Manufacturing are not the system itself. Rather, it is critical for people (and especially leaders at all levels) to understand the thinking behind the tools and artifacts.

The way Toyota teaches the thinking in their new plants is through structured experience. Key leaders are assigned coordinators as mentors. Leaders are taken to established plants to immerse into the system itself. The mentoring continues as the new plant is brought on-line. The process is long, resource intense and expensive. As a result the people who were trained this way are highly sought after in industry. (Another story for the future sometime.) Steven Spear’s article, “Learning to Lead at Toyota” does a great job giving the reader a feel for how this is done. The learning process is entirely experiential.

On the other hand, “talking head lecture” and PowerPoint slides are probably the least effective way to teach this stuff. Even with a couple of simulations with toy trucks or Legos, a classroom-only exercise is only going to get the general concepts across.

If you accept that the real learning comes from guided experience, then it follows to ask if the time spent in the classroom reduces the time required for experiential learning by at least as much. If a week in the classroom (plus the travel time, etc. away from the job) does not return at least two weeks of reduction in the hands-on learning, then it isn’t worth it… no matter how “feel good” it is.

What is the emphasis on direct observation of actual problems? One of the core skills for leaders to learn is how to see problems. If you ask “How much time is spent to watch and understand the work?” the answer you get will tell you a great deal about how well the trainer actually understands the TPS. A high-pressure “kaizen event” especially one which emphasizes just-do-something over first understanding the actual situation - is going to teach exactly the wrong things. Action without understanding results in chaos.

How much of the training involves making actual improvements to actual work?[sgl dagger] The more the better, but only in the context above.

The classic 5 day kaizen event was originally an educational exercise, and it works very well for this if it is planned and led with learning in mind.

What is the reputation of the teachers? Disregard client testimonials. Ask to speak to some long-term customers. I say long-term because in the initial stages of lean implementation things are pretty easy. A typical medium-sized factory, for example, can get most of the mechanics into place over a few months with aggressive leadership. But if the teachers do not understand (or understand and do not teach) the leadership how to detect, escalate and solve the thousands of problems that will inevitably be flushed to the surface, the implementation cannot sustain for long.

Recognize Reality: The only way to really lean this stuff is to through experience. And not just any experience. Just being told how to implement kanban, fill out the standard work forms, take cycle times, etc. is not learning the things you must know to sustain your gains and build on the initial momentum.

The critical skill - the one that (so far) is only learned through mentored experience - is how to direct actions through guidance and teaching vs. just telling people what to do or how to do it.

Invert the Problem

One very good idea-creation tool is “inverting the problem” - developing ideas on how to cause the effect you are trying to prevent. This is a common approach for developing mistake-proofing, but I just saw a great use of the idea for general teaching.

Ask "How could we make this operation take as long as possible?" Then collect ideas from the team. Everything on the flip chart will be some form of waste that you are trying to avoid. In many cases, I think, even the most resistant minds would concede that nothing on this list is something we would do on purpose.

It follows, then, that if we see we are doing it that we ought to try to stop doing it. And that is what kaizen is all about.