Is external wait time truly eliminated?

On p.49 you say that you have managed to eliminate wait time external to your processes. You also argue that you should focus on the internal processes and not the external processes as this is out of your control, which I partly agree with.

I, however, come from a Quality background and have a lot of UX design experience, so my perspective is grounded from the customer’s viewpoint.

From a customer point of view I don’t think waiting time has been eliminated. The entire service time is in fact waiting time from a customer perspective. Using the Disney reference (and with Gamification in mind), the way they solve this waiting time is by entertaining the user while they wait similar to an airport experience where users are asked to walk a certain journey to create the illusion that they are busy.

From a gamification perspective, this could be addressed by mapping out a user journey where the user is involved in the manufacturing process throughout the journey, not just at sales and then at delivery. IKEA has done this masterfully.

Taking the car manufacturing setting as example you could break down the sales process into smaller steps, mapped to the manufacturing production line. What do you need to know in order to start the manufacturing? Probably (and I’m assuming this because I haven’t worked in a car manufacturing plant myself) only the model. Next, you can ask for the configuration inside etc. In effect you’re stretching out the buying process to create the illusion that waiting time is reduced, even though it’s not. All you’re doing is getting information Just-In-Time rather than upfront before you start the process of manufacturing.

I realize there’s a lot of complexities, like the cost adjustments within different choices etc. but I think that’s a relatively easy problem to solve and could actually be more profitable.

So is external wait time truly out of your control and is it really eliminated? I’m not convinced.

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Karin, this is an extremely valid observation and a pain point for most teams and industries.

Here are my humble 2c to support you in this discussion.

  1. Is external time always out of control? By definition, yes it is. The adjustments you can do, be them by TameFlow or any other approach, is always on the system that you can influence most, and that is why we call such systems “internal”. The sad truth is that no matter how good your externally facing colleagues are, clients and service providers will always give priority to their own stuff before yours.

  2. Can these be really eliminated? With TameFlow you can always see that the buffer, the internal buffer, to your (internal) bottleneck is kept constantly in flow. If the real bottleneck is an external source, then I agree that there is a tough problem - and that is where risk assessments and escalations should occur.

These are my simple thoughts.

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Hi Karin

Thank you for your feedback!

Maybe the wording in the Chapter is not expressing the concept as I intend.

First, the customer perspective is never forgotten nor put aside.

What we are trying to do here is not to mix apples and oranges.

There’s a whole sector of this industry that pride themselves in how they improve Flow Efficiency - but if you then examine how that Flow Efficiency is calculated, they include the Wait Time that is outside of the actual Work Process. This is a mistake.

So what we are trying to do here is to set up the conditions whereby we can correctly measure Flow Efficiency. In that sense we “eliminate” (but please suggest better wording…) the Wait Time that is outside of the Work Process. We eliminate the external Wait Time from the calculation of Flow Efficiency. It does not mean that the external Wait Time implodes to nothing, nor that we are oblivious to its presence and/or effect on customer experience.

This is entirely in line with the distinction that TOC makes between the Span of Control and the Sphere of Influence.

All this does not mean that we don’t care about customer experience. Only that customer experience (Disneyland wait time) is simply out of scope if you want to deal with improving the Work Process via the Flow Efficiency metric.

Note though, that while it might be out of scope, if you are able to improve the performance of your Work Process many times over, then definitively the customer experience benefits as well. Nobody is happy to wait… even if they might be kept entertained while waiting! :slight_smile:

Does this make sense? Should I change some text somewhere to make this stand out better in that chapter or in other parts of the book?

Hi Steve and Matt,

I hear you, I’m just not convinced (being a Lean Production fan). But I’m only one and I’m sure most others will be convinced with your reasoning.:slight_smile:

According to me, the definition of Throughput is time from order placed to money in the bank. Excluding waiting time outside of the process that is in your control is ignoring part of the value chain. Part of what made the Toyota Way so successful is that they include the customers in their improvement endeavors. They start with the internal processes as this is obviously much easier, but they don’t ignore the externals.

Anyway, just a thought.

We need to be more specific. We call that Financial Throughput and we are very much concerned about that too when we look into Throughput Accounting. Besides if you look at the first diagram in Chapter 3, you can see that for TameFlow the definition of Lead Time is the time from order placement to payment; so there’s really no difference there.

In the chapter we are referring to, we are concerned with Operational Throughput. It is the counting of the widgets, not the counting of the dollars tied to the widgets! :slight_smile: Even though, we do show how that then translates into financial results.

We do include end to end considerations; no differently than Lean or TOC. (And in that, there is a whole lot more that we are not touching upon in this book.)

Even so, when you look at the Work Process (i.e. Span of Control) and want to improve how it is performed, we should not try to overextend our effort to what is outside of the Work Process. That is another exercise altogether.

I always find it saddening when there is this attempt at contrasting Lean and TOC. The latter builds on the former. For convincing evidence, maybe there is no more credible source than this: Nampachi Hayashi - Toyota Production System and The Roots of Lean.

End to end attention is no license to be relaxed or forgiving in what happens in between, and it is definitively no license to not focus on the details therein. Just because we are delving into those details of how to improve the Work Process, it does not mean we don’t pay attention to the bigger pictures. Only that they do not belong to this Chapter.

We are not ignoring the value chain. Please do not interpret this Chapter in that light. If the chapter gives you that impression, then I’m not writing it correctly; and would love to hear what I can do to improve it.