How to Determine Your Lot Size – Part 2

A good lot size has a significant impact on the performance of the system. In this second post, I look at the influence of the machine batch size on the lot size. I also briefly go into the lot sizes for the processing industry, and also  administrative processes. In my next and last post I will look at how to manage different lot sizes in different parts of the value stream. Continue reading How to Determine Your Lot Size – Part 2

How to Determine Your Lot Size – Part 1

There are a few factors that can influence lot size: machine batch size, changeover time, size of the container, shipment sizes, and the size of your customers’ orders, which then are combined in the set up of the information flow. All of these factors can be influenced to move toward the true north of lot size one! Also, do not confuse the lot size with the number of parts per kanban. They are related but can be different. In this series of three posts, let me explain in more detail how the factors come together for you to determine the lot size of your processes. Continue reading How to Determine Your Lot Size – Part 1

The Lean Bucket Brigade – Part 2: Details and Caveats

In my last post I explained the basics of the bucket brigade as a self-organizing manufacturing line. The key to making this system work is the process for handing over the part to the next worker. An unsuitable hand-over could mean lots of waiting time for the workers. Hence, I would like to go into more detail on how to do the hand-over of the part. Continue reading The Lean Bucket Brigade – Part 2: Details and Caveats

The Lean Bucket Brigade – Part 1: Overview

Many topics in lean address how to deal with uncertainty and fluctuations (or mura for unevenness). There is a particularly neat trick for manual lines that self-organizes fluctuations in the workload: the Bucket Brigade (also known as bump-back or bouncing line)! It does have some advantages, but it also has quite a few limitations and prerequisites for it to work. Most importantly it works best only for very short cycle times as for example picking materials. Unfortunately, these requirements are rarely mentioned in literature. Let me show you the basics work in this post before I go into some of the trickier details in the next post. Continue reading The Lean Bucket Brigade – Part 1: Overview

Dealing with Uncertainty

UncertaintyA lot of decisions in lean manufacturing have uncertainty. How many products will I sell (and what is my customer takt)? Which layout is more efficient? Should I believe expert A or expert B? Uncertainty is a part of life in manufacturing. In fact, the higher up you go in the hierarchy, the more you have to deal with uncertainty. And often these are not just simple “A or B” type of questions, but highly complex and interacting decisions like “What should our new line look like?” Here are some suggestions on how to deal with uncertainty. Please note that they will not answer all of your questions but will help you make better decisions. Continue reading Dealing with Uncertainty

How to Ramp Up a Kanban System – Part 2: The Switch

fotolia_on-air_trimmedIn my last post I described how to prepare for the implementation of a kanban system. This post goes into more detail on the actual change to the new kanban system. You surely know that every part should have a kanban. But what do you do if you have more kanban than parts? What do you do if you have more parts than kanbans? Find the answers below. Continue reading How to Ramp Up a Kanban System – Part 2: The Switch

How to Ramp Up a Kanban System – Part 1: Preparation

Simple Kanban LoopDesigning a kanban system on paper is much easier than implementing it on the shop floor. In many of my previous posts I discussed the design of a kanban system in detail. In these two posts I will discuss the steps needed to actually put the system on the ground.  This first post is the preparation, and my next post will be the actual switch to the new kanban system. Continue reading How to Ramp Up a Kanban System – Part 1: Preparation

Kanban Card Design

kanban-card-pileA kanban is, in its basics, information to reproduce or reorder parts. Hence, in its most basic form it has to say “make me this part” or “bring me this part.” While such very simple kanban systems are possible, usually it helps to include other information on the kanban card. In this post I want to talk about the design details of a kanban card, especially what kind of information we should include on the card. Please note that the items on the list below are suggestions. Which ones you actually include depend on the system you want to establish. Continue reading Kanban Card Design