It is thought that there is a limit of the time that human can keep concentration.

For example, Tadahito Kobayashi has argue that the maximum time for human concentration is 2 hours, so if a task takes over 2 hours, we need to divide it into smaller tasks and clarify the goal of each tasks.

To make full use of the 2 hour limit of concentration, some companies set the concentration-time on a companywide basis. For example, in a company Trump, they call the two hours of 12:30-14:30 "Gambaru Time". (*1)

It starts after lunch break every day and they prohibit communication. For example, instructions to subordinates, confirmation to superiors, and telephone calls outside the company are also prohibited. It is making sure that concentration is not interrupted by communication with others. By concentrating all around you, you are also easy to concentrate. Alto, it makes easier to plan your work.

Footnote *1: The Japanese word "gambaru" means "to do the best."