Creating Continuous Flow

The Creating Continuous Flow workbook helps managers, engineers, and production associates implement continuous flow production, a key objective of lean production.

     Like LEI’s other practical, plain-language workbooks, Creating Continuous Flow, answers the key question managers often have about lean tools and concepts, What do I do on Monday morning to implement this?
While many organizations in the aerospace, automotive, electronics, high-tech, medical device, and other industries are mapping product family value streams, they are struggling with the next step — creating flow at the pacemaker process. They have moved machines into U-shaped cellular layouts but flow is erratic and output fluctuates. Performance is better than in traditional layouts, but falls short of the potential gains from continuous flow, which include doubling productivity, halving space requirements, cutting throughput times by more than ninety percent, all while improving quality.
     Authors Mike Rother and Rick Harris lead readers through eleven simple but practical questions to show how to take full advantage of the transition from traditional processing departments to cellular layouts while achieving the full potential of cells already created.
Focus on the Pacemaker
     The new workbook explains how to organize and operate the critical pacemaker process in a way that supports continuous flow. Products take their final forms for customers at pacemaker processes, the most important place for developing flow.
     “Creating Continuous Flow is the next logical step after Learning to See,” said Harris. “The value-stream mapping process in Learning to See defined the pacemaker process and the overall flow of products and information in the plant. The next step is to shift your focus from the plant to the process level by zeroing in on the pacemaker process, which sets the production rhythm for the plant or value stream, and apply the principles of continuous flow,” said Harris.
     “Learning to See taught us about lean value streams, but you cant have a lean value stream without a well-functioning pacemaker process at the head of that value stream,” said Rother. “Creating Continuous Flow dives deep into the pacemaker process, an extremely critical point for achieving your future state lean value stream.”
      Every production facility has at least one pacemaker process, Rother explained. The pacemaker processes is where products take their final form before going to external customers. This usually occurs near the downstream or customer end of a value stream.
     “We call this part of your value stream the pacemaker because how you operate here determines both how well you can serve the customer and what the demand pattern is like for your upstream supplying processes,” said Rother.
      How the pacemaker process operates is critically important. A steady and consistently flowing pacemaker places steady and consistent demands on the rest of the value stream. The continuous flow processing that results allows companies to create leaner value streams. The reason is that continuous flow is the most efficient way of turning materials into products. Because items move immediately from one processing step to the next, the minimum amounts of resources and time are used, resulting in high productivity, quick response, and low cost.
      During their work at a wide range of manufacturing facilities, Rother and Harris report seeing little true continuous flow in the pacemaker segment of most value streams. Even though plants have been implementing cellular production for many years now, a closer look reveals most cells suffer from “fake flow” — erratic and intermittent flow of product, fluctuating inventory accumulations between steps, output varying from hour to hour, and poor use of human effort.
Eliminate Fake Flow
The Creating Continuous Flow workbook explains how to apply the principles of continuous flow by taking readers on a typical walk through an existing pacemaker cell in an example company, then posing a series of 11 questions. The process of finding the answers transforms the cell from “fake flow” to true continuous flow and produces a dramatic improvement in performance. The questions are:
1.Do you have the right products assigned to the pacemaker cell?
2.What is the takt time?
3.What are the work elements for making one piece?
4.What is the actual time required for each work element?
5.Can your equipment meet takt time?
6.How much automation should you use to create an efficient continuous flow?
7.How can the physical process be laid out so one person can make one piece as efficiently as possible?
8.How many operators are needed to meet takt time?
9.How will you distribute the work among operators?
10.How will you schedule the pacemaker process?
How will the pacemaker process react to changes in customer demand? Besides helping you create new cells, the information in the workbook also helps correct problems that hamstring the performance of existing cells. These fake flow problems include holding excess inventory between steps, incorrectly identifying work elements, and failing to distribute the work elements correctly among operators.
      The information in the 104-page text is supported by more than 50 illustrations, including charts, checklists, and diagrams. The six main sections of the book are:
1.Getting Started
2.What is the Work?
3.Machines, Material and Layout for Flow
4.Distributing the Work
5.Connecting to the Customer and Regulating the Flow
6.Implementing, Sustaining & Improving
Who Benefits
The final section on sustaining the hard-won gains helps you to prevent the cell from backsliding and offers guidelines for further improvements.
      Value stream managers, area managers, industrial engineers, manufacturing engineers, team leaders, supervisors, maintenance technicians, lean production specialists and production associates will benefit from the workbook. Frontline managers will appreciate the plan language and practical advice presented in it. The workbook also gives senior managers a better understanding of how lean thinking works at the process level.