In Lean processes, what does “waste” refer to?

In Lean processes, "waste" refers to any form of extra work that does not add value to the final product or service from the perspective of the customer. This concept is central to Lean methodology, which aims to streamline processes by identifying and eliminating waste to improve efficiency and productivity. By focusing on value-added activities, organizations can enhance customer satisfaction and reduce costs.

The definition of waste encompasses various categories, including time, resources, and activities that do not contribute directly to customer value. Therefore, the identification of "extra work" highlights the importance of looking critically at all steps in a process to ascertain whether they genuinely contribute to the customer experience.

The other options, while they may describe forms of waste, are more specific scenarios or types of waste rather than capturing the broader principle of waste as defined by Lean practices. For example, physical space for materials, waiting time, and excess inventory are indeed wasteful aspects of a process, but they are subsets of the wider concept that encompasses any unnecessary activity that does not enhance value.