Turning job shops into flow shops is not easy. This is my second post explaining such transformations as I try to help you in improving your shop floor from an (always) messy job shop into a much more efficient flow shop.
Job shops are always very difficult to manage. As I described in my previous posts, the irregular material flow causes fluctuations that are very hard to contain. In my view, the only true fix for a job shop is to convert it into a flow shop. In this post I will talk a little bit about how you approach the idea of converting a job shop into a flow shop … although this is not always possible. However, in many cases it is possible to increase flow-shop-like segments, even though the whole system is still a job shop.
Job shops are a mess. Period. The increased and uneven levels of inventory cause a host of other problems. In my last post I described how these inventory imbalances are caused by irregular material flow, how subsequent safety buffers increase inventory even more, and how this causes staff to change their workplace irregularly in a job shop. In this post I will continue the long list of ills in a job shop with staff changeover losses, extra searching and organizing, fluctuating lead times, and general un-plannability of job shops.
Job shops have a strong tendency toward chaos. Even well managed plants struggle to maintain order in a job shop. This is due to the inherent nature of a job shop, and there are no good solutions to manage job shops. The only good way to improve a job shop is to turn it into a flow shop. I will talk more about such changes later in this short series, but first let me explain why job shops are always a mess.
Pull production is a highly useful tool in manufacturing, logistics, services, and other industries. However, there are instances where pull may be not the best option. These instances are rare, but they do exist. In this blog post I will list different cases when pull may not be the best option.
In my last two posts I showed you fixed location storage and its disadvantages, random chaotic, and ABC storage. But there is more. Another option is some sort of combination of fixed location, random chaotic, and ABC storage. Let’s look at some of the variants.
In my last post I looked at the disadvantages of fixed location storage. Usually much better is random chaotic storage. This is, for example, the preferred method of Amazon. This approach makes best use of the available space and generates less mistakes. When Amazon started using this, they reportedly were able to store twice as many items in the same space as as before.
In my last post I looked at different ways to store material. This post is a continuation, looking at where to put materials. I want to give an overview of the different options to help you choose one that is suitable for your situation. This first post looks at storage with fixed locations, and why this is usually not so hot.