Card-Based Control Systems for a Lean Work Design

The Fundamentals of Kanban, ConWIP, POLCA, and COBACABANA

Matthias Thurer, Mark Stevenson, Charles Protzman

• Publisher: Productivity Press
• Year: 2017
• eBook ISBN: 9781498788342
• Topic: Business
• Subtopic: Operations
• Index: Business

Many shops have simplified their production control by using card-based systems such as kanban and Constant Work-in-Process (ConWIP). Although these systems provide a simple and highly effective visual approach for controlling manufacturing and service operations, all too many shops struggle with failed implementations or achieve results that fall

Chapter 1

Basic Concepts

Highlights

• We outline how we conceptualize a production/service system and the business operations/processes executed.
• We outline what a card-based control system does.
• We outline what a card-based control system does not do.
• We make some important points concerning why you should choose a card-based control system rather than the latest technology.

This book promises to be different. Earlier books have typically focused on one particular card-based control system before presenting environments where it is argued that they provide the best solution. This creates the approach of putting the solution ahead of determining the problem.

In contrast, we first discuss how to diagnose a problem and then discuss a range of possible solutions from which to choose. This seems more logical, but it is a much more complicated task, since we cannot start directly by presenting a well-defined solution. Rather, we first have to build the foundations for diagnosing the problem that your shop is faced with; and we must do this for a problem that we all know is quite complex:

The coordination of product/service flows through a set of capacity resources, in your shop, that transform materials, people, information, etc., into final products/services.

From here on in, we call this “the control problem.” This control problem is complex since resources are typically scarce and/or constrained; and because different product/service flows often compete for the same resources.

Before starting any diagnosis, we must take a step back and introduce some basic concepts. We first need to understand how a production/service system can be described. This then clarifies the role that card-based control systems can and cannot play in supporting such a system. It is also important that we use the same concepts throughout the book to provide the required clarity. You may find this somewhat technical, but bear with us. We will use a lot of “timeouts” to give you some breathing space, some time to conceptualize things and perhaps to relate them to your own shop.

You may agree or disagree with our conceptual definitions. That is fine. There is no “true” conceptualization of a production/service system. But what is important is that you understand how we define and use the concepts in this book. Only this will make our suggestions on how to diagnose a control problem (and consequently use the most suitable control solution) clear. But let’s just start.

What Is a Production/Service System?

We start by looking at the different parts that constitute a production/service system. We will first approach this from the perspective of the product/service. Thus, we describe a production/service system in terms of its product/service flows. In doing so, it is common practice to start with the input to a product/service flow. But we arbitrarily turn this around and start with the most important aspect—the customer. So let’s define the first five concepts that will be used in this book to describe a product/service flow.

The Customer

One of the primary objectives of any company is to make money. Environmental and social responsibility is also important, but firms also do not need to be ashamed of the desire to be profitable. To make money—someone has to be willing to pay for something. The “someone” is the customer. The “something” is the product/service. Even though we say someone is willing to pay, sometimes no real payment takes place; for instance, if we refer to an internal customer belonging to the same company, department, operation, etc.

The Product/Service

The output is the product/service or range of products/services that you sell. If you don’t sell the product, it has to be scrapped; if you don’t sell the service, you waste your time (and time is m...

Table of contents

• Preface
• Acknowledgments
• Authors
• Chapter 1: Basic Concepts
• Chapter 2: Basic Principles Underpinning a Card-Based Control System
• Chapter 3: Simplified Scheduling through Pool Sequencing and a Shop Floor Dispatching Rule
• Chapter 4: How to Diagnose a Control Problem?
• Chapter 5: The Inventory Control Problem: Kanban Systems
• Chapter 6: The Low Variability Order Control Problem: ConWIP
• Chapter 7: Inventory Control Plus Material Requirements Planning for the Order Control Problem: POLCA
• Chapter 8: How to Solve the High Variety Order Control Problem: COBACABANA
• Chapter 9: COBACABANA’s Card-Based System for Delivery Time Estimation
• Chapter 10: Summary: Framework of Applicability
• References
• Appendix: Summary of Card-Based Systems