In time management, this theory is also called the “bucket of rocks” or the “jar of life” theory. Jeremy Wright introduced the concept in 2002, stating that time — like space in a jar — is limited. As such, we need to strategically fill our jars with the right ingredients to accomplish the most important tasks.

The rocks are your priorities, while the other things in your life are represented by pebbles and sand. In order to stay productive and efficient in your personal and professional life, it's best to have a maximum of five rocks in the jar at any given time.

The big rocks are your strategic goals – like developing new products. The sand is the minor tasks like email, unjamming the printer, and having meetings to plan the agenda for the next meeting. The pebbles fall somewhere in between. If you want to get your big rocks into the jar, you need to put them in first.

The size and importance of your tasks are represented through four elements: Rocks, pebbles, sand, and water. The rocks: Say hello to the most important tasks in your workday. These to-dos will be bigger than others, so they’ll take up more space in the jar (more time). Make them your priorities.

This jar is represents your life. The big rocks signify the really important things in your life, such as health family and friends. The pebbles are the other things that matter in your life, such as work or school. And the sand signifies the remaining small stuff, such as material possessions.