GTD rests on the principle that a person needs to move tasks out of the mind by recording them externally. That way, the mind is freed from the job of remembering everything that needs to be done, and can concentrate on actually performing those tasks.
GTD is defined by David Allen on his website. In traditional time management, priorities usually play a central role. In contrast, Allen promotes two key elements in his version of time management — control and perspective. Allen advocates three major models for gaining control and perspective:
The first major model is the workflow process, which is used to gain control over all the tasks and commitments which one needs or wants to get done. The workflow process consists of five distinct phases listed below (with each described in greater details in the Principles section):
Allen uses an altitude analogy to illustrate his second major model, 6 different levels of focus, and give perspective on tasks and commitments. These 6 levels of focus, from the bottom up, are:
As one ascends in altitude, one is able to consider the "bigger picture." Considering projects, actions, unfinished business or commitments ("open loops" in GTD terminology), and other "input" from a variety of "heights" gives one varying perspective.
Allen advocates a weekly review focused on different levels. The perspective gained from these reviews should drive one's priorities, which in turn determines the priority of if and when one is to do the particular individual tasks and commitments gathered during the workflow process. During a weekly review, the user determines the context for the tasks and places them on the appropriate lists. Examples of grouping together similar tasks include making a list of telephone calls to make or errands to do while downtown. Context lists can be defined by the set of tools available or by the presence of individuals or groups for whom one has items to discuss or present.
Allen expects that the first two models are sufficient most of the time to gain control and perspective on the majority of tasks and projects. However, there are some cases in which more involved planning and thinking are necessary. This leads to the third major model, which is the natural planning method. While the workflow model has a "horizontal" focus on doing individual tasks, the natural planning method has a "vertical" focus on planning projects and thinking through topics. The planning model consists of 5 stages:
GTD is based on making it easy to store, track and retrieve all information related to the things that need to get done. Allen suggests that many of the mental blocks we encounter are caused by insufficient 'front-end' planning (i.e., for any project we need to clarify what is to be achieved and what specific actions are needed to achieve it). It is most practical, according to Allen, to do this thinking in advance, generating a series of actions which we can later undertake without any further planning.
Allen contends that our mental "reminder system" is inefficient and seldom reminds us of what we need to do at the time and place that we can do it. Consequently, the "next actions" stored by context in the "trusted system" act as an external support which ensures that we are presented with the right reminders at the right time.
A capsule description of GTD from Allen's book Ready for Anything:
Get everything out of your head. Make decisions about actions required on stuff when it shows up — not when it blows up. Organize reminders of your projects and the next actions on them in appropriate categories. Keep your system current, complete, and reviewed sufficiently to trust your intuitive choices about what you're doing (and not doing) at any time.
Allen doesn't advocate any preferred collection method, leaving the choice to the individual. He only insists upon the importance of emptying the "buckets" regularly. Any storage space (physical inbox, email inbox, tape recorder, notebook, PDA, etc.) that is processed regularly by the individual is acceptable.
A calendar is important for keeping track of appointments and commitments; however, Allen specifically recommends that the calendar be reserved for the hard landscape: things which absolutely have to be done by a particular deadline, or meetings and appointments which are fixed in time and place. To-do items should be reserved for the next action lists. A final key organizing component of GTD is the filing system. A filing system must be easy, simple and fun. Even a single piece of paper, if needed for reference, should get its own file if it doesn't belong in an existing folder. Allen suggests a single, alphabetically organized filing system, in order to make it as quick and easy as possible to store and retrieve the needed information.
At least weekly, the discipline of GTD requires that all outstanding actions, projects and 'waiting for' items are reviewed, making sure that any new tasks or forthcoming events are entered into one's system, and that everything is up to date. Allen suggests the creation of a "tickler file" in order to help refresh one's memory each week with the outstanding tasks and projects.
One device that Allen suggests is the tickler file for organizing paperwork (also known as the '43 folders'). Twelve folders are used to represent each month and an additional 31 folders are used to represent each day. The folders are arranged to help remind the user of activities to be done that day.
... less structured and more functional applications will emerge in the coming years, based on the ways we naturally think and plan.
Since that prediction, a virtual explosion of GTD-supporting software has emerged; in April 2008, more than 100 applications provided the core features for implementing Getting Things Done. These tools now range from simple list managers to collaborative web services, both free and commercial, for all popular platforms and devices. Much of this software specifically automates or reinforces the GTD methodology of collecting, processing, organizing, reviewing, and doing.
Some followers of GTD advocate a 'back-to-basics' approach to personal management, and a rejection of over-engineered, high-tech solutions in favor of simple, less-expensive tools such as preprinted cards, index cards, the Hipster PDA, or even the Moleskine paper pad. David Allen himself says he relies on a "vanilla" Palm PDA and records "events of the day" on paper to be processed later.
In 2005, Ben Hammersley interviewed David Allen for The Guardian, with an article called "Meet the man who can bring order to your universe", saying "For me, as with the hundreds of thousands around the world who press the book into their friends' hands with fire in their eyes, Allen's ideas are nothing short of life-changing."
In 2007, Time Magazine called Getting Things Done the self-help business book of its time, a contrast to the notion that GTD has only a niche following of zealous enthusiasts.
In 2007, Wired ran another article about GTD and Allen, quoting him as saying "the workings of an automatic transmission are more complicated than a manual transmission, [t]o simplify a complex event, you need a complex system." The author of the article, Gary Wolf, dug into the roots of GTD, covering Allen's stay in a mental hospital and his encounters with several New Age gurus, including Sri John-Roger who created the Movement of Spiritual Inner Awareness, in whose church Allen is still a minister.