Which of the following describes ‘delays’ in a lean context?

In a lean context, 'delays' specifically relate to the time that work is waiting to be done, which is referred to as 'waiting time' in lean terminology. This concept emphasizes identifying and minimizing any periods when work is not progressing, which can severely impact efficiency and flow in a production or service environment.

By focusing on how long work is in a state of waiting, organizations can pinpoint inefficiencies in their processes. This focus on eliminating waiting times aligns with the lean principle of maximizing value by minimizing waste. Properly managing these delays can lead to increased productivity and better utilization of resources, which are key goals in lean methodologies.

The other options describe various forms of time management but do not encapsulate the specific nature of delays as understood in a lean framework. For instance, purchasing time and project timelines are broader factors that do not directly address the issue of work-in-progress waiting to be acted upon, which is critical for optimizing flow in lean practices.