In my last post, I talked about the value of time in manufacturing, focusing on cyclic or repeatable times. However, the bigger problems are often non-cyclic or fluctuating times. The main difference is that non-cyclic work is a fluctuation, and it causes all kinds of other waste, from excess inventory to additional waiting times. On the other hand, depending on how often the fluctuation happens, there may not be so much benefit in reducing its duration. Read on…
Fluctuations
Never Skip a Step in a Chaku Chaku Line!
Chaku Chaku lines and many other manufacturing cells and manufacturing lines have one (or more) operators working on different processes throughout the cycle. However, with this multi-machine handling, a worker must not skip a process if there are technical problems. Doing so—even with the best intentions—will increase fluctuations and cause waste. Let’s have a look at an example of why skipping steps is not so good.
Fluctuations on Continuously Moving Assembly Lines 3—The Value of Team Leaders
In my last two posts I described the impact of fluctuations on the duration of the work on a continuously moving assembly line. One key tool for reducing fluctuations on Toyota assembly lines is the team leader, the frontline support for operators. Team leaders reduce fluctuations in general by taking over irregular tasks like delivering material, taking away trash, and explaining situations to a manager. They also reduce especially long fluctuations by supporting the operators in their own work if there are problems, thus reducing stops of the line. This post will look in more detail at the beneficial effects of team leaders on a moving assembly line.
Fluctuations on Continuously Moving Assembly Lines 2—Waiting Times
In my previous post I posed the problem of decoupling fluctuations on continuously moving assembly lines. You cannot decouple using inventory; you can decouple only long-term fluctuations using capacity, while all other fluctuations are decoupled using time. In my last post I introduced the topic and urged you not to have workers between different stations to handle fluctuations. In this post I will look in more detail at the waiting time of the workers due to fluctuations in the work duration for the stations.
Fluctuations on Continuously Moving Assembly Lines 1—Don’t Move the Workers Around!
A lot of industries use continuously moving assembly lines. This is common in automotive, but also in many others. The challenge is to manage the fluctuations. You cannot decouple using inventory; you can decouple only long-term fluctuations using capacity, while all other fluctuations are decoupled using time. This is the first blog post of a series digging deeper into how to handle or NOT handle fluctuations on continuously moving assembly lines. This first post looks at the effect when workers move among different stations.
Toyota Change Point Management: Henkaten
Henkaten is an approach by Toyota to deal with changes in their manufacturing system. It is one of the lesser-known words of the lean vocabulary. Often translated as “change point,” it is about managing a change. However, there is no magic behind yet another Japanese word. It is all just the basics like most methods in lean manufacturing: attention to details, standards, and visual management. Let me show you!