We have explained the lean operation concepts in our previous blog post. This round, we are going to study on wastes in lean operation. In the principles of lean operation, wastes are non value-added activities. In other words, wastes are activities that do not bring values to customers, and are considered a burden to the process.
Traditionally, manufacturers can tolerate with the production of defective parts or inventories that need to be reworked. But as noted by the father of Toyota Production System (TPS), Taiichi Ohno, any process or parts that do not add value to customers and customers do not wish to pay for it, is considered a waste. Ohno has identified seven categories of waste that forms an important part of lean thinking. The seven categories of waste are:
- Over-production: this waste refers to condition were companies are producing more than what is expected or ordered by the customers or over-produced inventories. Inventories of any kind, be it a work-in-process (WIP) or finished product, are considered waste.
- Waiting or Queues: situations such as waiting time between production processes, machine Idle time, waiting time associated with storage and retrieval, interruptions during production shift change, etc. These are situations that add no values.
- Transportation: inefficient material movements between plants or between work centers, moving products that are not actually required to perform the processing, etc.
- Inventory: all raw materials, work-in-process (WIP), finished goods, and excess operating supplies are considered as waste when inventory related cost (such as storage costs and handling costs) are significant.
- Motion: Movement of equipment or people that is more than what is required to perform the processing is waste.
- Over processing: additional work or process that is performed on the product. This can be due to poor tools or inefficient workflow design that adds no value to the final product.
- Defective product: product returns, warranty claims, rework and scrap are considered a waste as it requires extra resources for inspecting and fixing defects.
Do you know how to identify them in your organization? You are invited to join our event “Lean Journey to Productivity“, as we take you on a journey to lean. The event is free and on a first come first serve basis. Find out more by register this event today.