Muhammad Ali once said, “What keeps me going is goals.” But what keeps a goal going? Before setting an objective, it helps to understand the three insights that differentiate the paths to success and failure.

Know Your Goal

Vague goals are elusive goals.

Instead of thinking in general terms, hone in on what you really want to accomplish. The time-tested SMART acronym offers good criteria. Realistic objectives are typically Specific, Measurable, Attainable, Relevant, and Timely.

Long shot: Wanting to be “more successful” is reasonable, but it’s a futile goal. The definition of successful is broad. It’s difficult to measure. Without specifics, it’s unclear whether the goal is even attainable.

Attainable: Focus on what success means to you. Do you want to be promoted to a senior management position within the next six months? Are you lusting after a Top Salesperson of the Year award? Those goals are explicit, and they include a definitive target and timeline.

Know Yourself

Next, consider your intentions. In Psychology Today, psychologist Clifford N. Lazarus says, “You need to assess your interests, abilities, and goals, and take an honest self-inventory.” Foster your strengths, because unrealistic expectations can kick off an endless uphill battle.

Long shot: Joining the American Ballet Theatre is a lofty dream. If you’re a 40-year-old physician who clocks in at six feet tall, this might not be the year to attempt it. Even Michael Jordan has limitations (see: the basketball legend’s short-lived baseball career).

Attainable: Pinpoint what about your aspiration appeals to you, in this case the physical challenge or thunderous applause. Now, reconcile that with your passion and talent. Perhaps committing to an Introduction to Ballet class would be an equally satisfying aim. Or, appearing in the local production of Swan Lake might be a reasonable—but just as rewarding—finish line.

Know Your Surroundings

Margaret Andrews, president of Mind and Hand Associates consulting firm and instructor for the Harvard Extension Professional Development Programs, suggests considering “what or who else is involved—and has to fall into line—for you to reach your goal.” Even the best intentions can meet insurmountable roadblocks. Find a way around them before they materialize.

Long shot: According to Nielsen, over 67 percent of US consumers aspire to exercise more in the new year. What could possibly go wrong? It turns out quite a bit, especially if you work 12-hour days, live 25 miles from the nearest gym, or reside in a climate that prohibits outdoor workouts half the year.

Attainable: Identify potential challenges from the get-go, and factor methods of defeat into your strategy. Lunchtime laps around the office parking lot, for example, can replace time spent in a gym five towns over.

There typically isn’t one means to an end. And, if you know your goal, yourself, and your surroundings, success is always within reach.