Just in Time (or JIT) is a powerful method to reduce costs and increase efficiency. However, it is also very difficult to achieve. Most times when a Western company tells me it does JIT, it turns out that this is merely wishful thinking. Let me tell you what JIT really is. I will also talk a bit about the history of JIT. Finally, I will show you a few negative examples of wishful thinking common in modern industry. In my next posts I will go into more details on how to make it work.
To manage your shop floor (or any other part of your enterprise), you need to have reliable data about the situation on the shop floor. Even with reliable data, the remaining uncertainty makes good management a challenge. Many managers, to save precious time, rely on data and information provided to them by their people. This is a grave mistake! Always verify at least part of the data with you own eyes! You would be surprised how different – and usually worse – it is in reality.
In the last post I described how to balance a line using pen and paper. This description was a basic, straightforward approach. In this post, I will enhance it with a few tips and tricks for balancing a line. Also, I will briefly describe how to balance a line using computers and then tell you why I much prefer the paper version.
The previous four posts in this series for line balancing all looked at how to prepare the data and do some initial calculations. You could balance the line using a computer or – much better – do it using paper. In this fifth post, we now actually start to balance the line though shifting around small pieces of paper. In the next post I will show you some important tricks, and also how to do it on a computer (bah!).
In the previous post we looked at the potential problems when using an OEE for line balancing. Now, in the fourth post on line balancing, we actually use the OEE to create target cycle times (or, alternatively, a target line takt) for our system before we start balancing the system in the next post.
When balancing a line, it is important to distinguish between idealized times without losses, and times that include all types of losses like breakdowns or missing material. The ratio between the ideal time and the real time is the OEE. This post looks at some of the problems that can happen with line balancing if an OEE is used incorrectly or differently, and is the third post on this series of line balancing. Once we have determined what OEE to use, we will look at how to use the OEE in line balancing in the next post.
In our first post on line balancing, we looked at the tasks that must be included in the line. In this second post of this series on line balancing, we look at the durations for the individual tasks. Of particular interest are different strategies on how to balance a line if the tasks have different durations for different products. A second consideration is if the equipment is already available or is still to be purchased (and hence can be customized more). The next post will look at more details of the losses (i.e., the OEE).
Balancing the workload in a manufacturing system helps greatly in improving performance. Most importantly, it reduces unevenness (mura) due to different workloads. This in turn will reduce wasted waiting time (muda) for those with too little work, and overburden (muri) for those with too much. Additionally, I usually find it to be one of the easier aspects of lean manufacturing, since the new standard can simply be enforced through the layout of the machines. This post looks at data preparation, especially the customer takt and the list of tasks. It will be the first in a long series of posts on line balancing. The next post will look at the durations needed for the tasks.