In lean methodology, what does "waiting" refer to?

In lean methodology, "waiting" specifically refers to idle time in processes or tasks. This term captures the non-value-added duration that occurs when work is not progressing. For instance, waiting can happen when employees are held up due to bottlenecks in production, needing material that is not available, or awaiting approvals. This idle time is detrimental because it reduces productivity and can increase costs without contributing any value to the end product or service. In essence, minimizing waiting times is crucial in lean principles to enhance efficiency and ensure that every moment of work is utilized effectively.

The other situations described, such as time spent in transit, excessive paperwork, or unnecessary meetings, may also represent inefficiencies in a process, but they do not capture the specific connotation of "waiting," which is focused explicitly on inactivity or stalling in workflow.