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Stability


“Stability.” If the processes were stable, we could do a lot more things. The barrier created by not having a steady process is more significant than we think. Most projects start with some improvement of instability. And many struggles to accomplish stability and try to live with instability. But instability wears out the organization. We need stability.


Talking about stability, we should talk about one bias. We believe that the more resources, the more stability we have. This statement is not valid. With more resources, individual resources remain unstable. Collectively, the maximum capacity went up, but the stability remained the same. The only reason the stability went up by adding the resources is that they planned better when they added the resource. Think about the difference between a mob and troops. Or history proofs that the number of troops does not necessarily predict the outcome of a battle. The more controlled troops usually win (there are cases where the barbarians beat the troops, but many of that is caused by corrupted control). The number of resources does not guarantee the outcome. The only thing that more resources guarantee is an increase in cost.


Stability comes from good standards and management. This is the reason why when you “plan” better, you gain stability. But what is a “good” standard?


“Good” standard is not about calculations. Many have tried to add some margins to standards to stabilize a process. However, such calculations fail because the future condition will differ from the reference point in the past. Just because your historical stability was 60% does not guarantee that you remain at 60%. It could go up or down. Taiichi Ohno points out another interesting view on using an average time.

Drop a nut once and pick it up. Working at the average time is like trying to catch the nut halfway because letting it drop all the way down takes too long. Who could do such difficult work? You can do the work in the shortest time if you ask, “Why did I grip the nut in a way that made me drop it?” and, “Is there a method to grip the nut more securely?” This will also be the easiest motion. Or you may find that people are pacing themselves because if they do a lot of work their workloads for the day will increase.

[Ohno, Taiichi(2013). Taiichi Ohnos Workplace Management: Special 100th Birthday Edition (pp.145-146). McGraw-Hill Education.]

This wisdom applies to any calculations. Average, 20%, 60%, 100%. It doesn’t matter. Calculations do not help make the process stable. Instead, it makes the process more unstable by delaying the recognition of an unstable cause. Once these delays become the norm, there will be this mental buffer between processes and management that it’s okay to have instability. It leads to a condition where people do not respect any rules, destroying standard after standard.


“Good” standard should form “Points,” “Lines,” and “Areas” in reality.

“Points” are “Who,” “Where,” “When,” and “What” specified to a precise point. It can’t be ambiguous and make the points disappear. For example, during the start-up of the shift, we need to specify “Who” needs to be “Where” and “When.” An operator needs to scan their badge, attend the kick-off meeting, and go to each station. Suppose the shift kick-off meeting starts at 6 AM, then all operators must complete badge scan be at the meeting zone at 6 AM. If this is not respected, the meeting time is a waste. The locations of these badge scanners and meeting zone must be reachable within a set time. And then define “What” needs to do.

Once the above points are defined, the movement & tasks form a line. Each movement and tasks need to have a standard time. These lines need to be logical. Once there was a process when an operator was supposed to do some cleaning before the shift. The quality team told the same operators to perform process checks. The maintenance team designed TPM tasks for the same operators, which standard time was 30 minutes. The total allocated time for all these activities was 15 minutes. There were discussions about why operators’ “culture” does not respect these standards, but it was simply impossible.

The above movement & tasks with a standard time should form the standardized work. Here what I mean is to make the work repeatable. Very often, a person’s mission at the beginning of a shift is to search for something. They search for materials, labels, information, etc. For example, I had an opportunity to observe a shift change at a hospital. Once the meeting finished, the doctors and nurses started searching for the computers. One found one laptop without power. One logged in to the laptop that some else already signed in. So later, the original owner of the laptop started searching for it again. Where should the laptops be at the end of the shift? Should we power it up or not? Do we have enough time to charge the batteries? If not, do we have backups laptops for charging time? If we standardized these points and made the work repeatable, the start of the shift would become stable.


Stability. It’s a topic that I think we should discuss more.

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