David Allen’s Getting Things Done was hailed as ‘the definitive business self-help book of the decade’ when it was first published fifteen years ago.

Next Action Associates, the only company in the UK and Ireland certified to teach the GTD methodology, is this month launching a new edition of David Allen’s best-selling book, Getting Things Done: The Art of Stress-Free Productivity, published in the UK by Piatkus.

The extract below is a chapter from the new edition, updated to reflect the huge changes in the business world over the last 15 years.

Let’s assume for a moment that you’re not resisting any of your stuff out of insecurity or procrastination. There will always be a long list of actions that you are not doing at any given moment. So how will you decide what to do and what not to do, and feel good about both?

The answer is, by trusting your intuition. If you have captured, clarified, organized, and reflected on all your current commitments, you can galvanize your intuitive judgment with some intelligent and practical thinking about your work and values.

>See also: How to make the most of your home office

There are three models that will be helpful for you to incorporate in your decision making about what to do. They won’t tell you answers—whether you call Mario, e‑mail your son at school, or just have an informal conversation with your secretary—but they will assist you in framing your options more intelligently. And that’s something that the simple time-and priority-​management panaceas can’t do.

1. The Four-​Criteria Model for Choosing Actions in the Moment

At 3:22 on Wednesday, how do you choose what to do? At that moment there are four criteria you can apply, in this order: context, time available, energy available, and priority.

The first three describe the constraints within which you continually operate, and the fourth provides the hierarchical values to ascribe to your actions.

Context You are always constrained by what you have the capability to do at this time. A few actions can be done anywhere (such as drafting ideas about a project with pen and paper), but most require a specific location (at home, at your office) or having some productivity tool at hand, such as a phone or a computer. These are the first factors that limit your choices about what you can do in the moment.

Time Available When do you have to do something else? Having a meeting in five minutes would prevent doing any actions that require more time.

Energy Available How much energy do you have? Some actions you have to do require a reservoir of fresh, creative mental energy. Others need more physical horsepower. Some need very little of either.

>Related: Increasing productivity through office experience

Priority Given your context, time, and energy available, what action remaining of your options will give you the highest payoff? You’re in your office with a phone and a computer, you have an hour, and your energy is 7.3 on a scale of 10. Should you call the client back, work on the proposal, process your e‑mails, or check in with your spouse to see how his or her day is going?

This is where you need to access your intuition and begin to relyon your judgment call in the moment. To explore that concept further, let’s examine two more models for deciding what’s most important for you to be doing.

2. The Threefold Model for Identifying Daily Work

When you’re getting things done, or “working” in the universal sense, there are three different kinds of activities you can be engaged in:

• Doing predefined work
• Doing work as it shows up
• Defining your work

Doing Predefined Work When you’re doing predefined work, you’re working from your Next Actions lists and calendar — completing tasks that you have previously determined need to be done, or managing your workflow. You’re making the calls you need to make, drafting ideas you want to brainstorm, attending meetings, or preparing a list of things to talk to your attorney about.

Doing Work as It Shows Up Often things come up ad hoc – unsuspected, unforeseen – that you either have to or choose to engage in as they occur. For example, your partner walks into your office and wants to have a conversation about the new product launch, so you talk to her instead of doing all the other things you could be doing. Every day brings surprises—unplanned-​for things that just show up—and you’ll need to expend at least some time and energy on many of them. When you follow these leads, you’re deciding by default that these things are more important than anything else you have to do at those times.

Defining Your Work Defining your work entails clearing up your in-tray, your digital messages, and your meeting notes, and breaking down new projects into actionable steps. As you process your inputs, you’ll no doubt be taking care of some less-​than-​two-​minute actions and tossing and filing numerous things (another version of doing work as it shows up). A good portion of this activity will consist of identifying things that need to get done sometime, but not right away. You’ll be adding to all of your lists as you go along.

>See also: How to influence without authority

Once you have defined all your work, you can trust that your lists of things to do are complete. And your context, time, and energy available still allow you the option of more than one thing to do. The final thing to consider is the nature of your work, and its goals and standards.

3. The Six-​Level Model for Reviewing Your Own Work

Priorities should drive your choices, but most models for determining them are not reliable tools for much of our real work activity. In order to know what your priorities are, you have to know what your work is. And there are at least six different perspectives from which to define that. To use an appropriate analogy, the conversation has a lot do with the horizon, or distance of perception. Looking out from a building, you will notice different things from different floors.

·         Horizon 5: Purpose and principles

·         Horizon 4: Vision

·         Horizon 3: Goals

·         Horizon 2: Areas of focus and accountabilities

·         Horizon 1: Current projects

·         Ground: Current actions

Further reading on productivity: How to be successful – Morning routines matter!