By fixing the amount of time we spend on a given set of tasks, we can focus on doing the things that matter, give us motivation to start, prevent overruns and use our “null” times effectively. In contrast, if we worked on things until completion in one sitting, we’re less likely to start on complex tasks, more likely to overrun on open ended tasks and leaves us with less time and motivation to work on the next set of tasks.

Source: David Seah