Tech Talk
What is lean manufacturing and 5S? Explain some of the terminology surrounding these concepts.
5S The 5Ss are the pillars of eliminating waste—they are exposed as work becomes organized. The five Japanese words relating to standards for work area organization: Sort (seiri), Set (seiton), Shine (seiso), Standardize (seiketsu), and Sustain (shitsuke). Andon An Andon is a horizontally stacked series of: red (stop), yellow (caution) and green (go) lights representing work centre status. This visual control is used to simplify operation management. “Caution” may indicate a work centre in training, or evaluating some aspect of the work, preventing it from responding at top capability. Cell A Cell is a group of machines or equipment, with a defined flow, in a group composed to complete an entire operation or major production step. Cells combine different types of equipment and processes, thereby breaking down functional groupings of like machines. If setup times are reduced to make smaller batches, the cell reduces wait, thereby moving and handling waste enabling faster response. The most recognized form is a ‘U’ shaped cell. Control Chart In the 1950s, Dr. Edward Deming’s quality principles revolutionized Japanese manufacturing by illustrating that systemic drivers accounted for 85% of quality problem; eliminating systemic problems and variations in the manufacturing process, rather than concentrating on the few errors created by humans. Deming’s control charts revealed how actual specific parametres (e.g., measurements) can be plotted on a time graph to show trends and situations where the upper (UCL) or lower (LCL) control limits are passed. Kaizen Kaizen is an effort to identify and eliminate waste. In the U.S., we typically use the term to describe the activity of analyzing work (e.g., a kaizen event). During a “kaizen event”, work is organized into it component steps in order to identify waste. Once identified, attention is focused on ways to eliminate the unnecessary steps and non-value added activities. JIT Just in Time (JIT) combines pull production with other waste elimination—most notably setup time reduction—to better connect production to actual upstream (customer) usage. Kanban Kanban literally means card or tag. Kanbans are physical controllers that communicate “what”, “when” and “how much” to make. When material is consumed upstream, the kanban is sent back to signal making more. There are many types and ways of using kanbans. Muda Muda means waste—and there are seven fundamental forms: motion, waiting time, over production, processing, defects, inventory and transportation. Poka-yoke Poka-yoke are methods to foolproof an operation by checking for quality errors (e.g., a transportation cart that can only fit in if they were made correctly, such as the correct diametre or keyway location). Pull Production that is initiated by the actual consumption of product by: 1) an upstream work centre or, 2) the customer. The pull signal (a kanban) may be issued after a certain amount of product is consumed (which is the kanban production quantity). Reducing setup times for small batch sizes and high quality levels are critical to accurately replenish based on pull signals. Push Production is planned and initiated based on forecasts of customer usage, current production orders and inventories. It is typically calculated using an enterprise resources planning (ERP) system. Forecasts, bills of material, production Work in Process (WIP) tracking and inventory accuracies are critical for planning. Production is initiated by an order from the office to the plant floor. SMED Single Minute Exchange of Dies (SMED), relates to the dramatic transformation of setup times for large stamping dies, from eight or more hours to single minutes, which enabled pull production in stamping plants. TPS TPS means Toyota Production System. Suppliers to Toyota use this term often, rather the Lean Manufacturing, but the concept of TPS are the original principles of Lean. Takt Takt is the time, per part, being consumed or sold per unit of operating time. This differs from cycle time, so think in terms of time “available” compared to how many are “needed”. Think of matching the pace of your production to customer consumption. Basically, you want to vary (customize) your rate of production, reducing the hours devoted to it, based on the rate at which customers pull. In simple terms, how to run an efficient operation at different Takt rates?
