Do you want a long-lasting, successful marriage, one that keeps you fulfilled for years after the wedding guests have gone home and the first blush of romance has worn off? Here's one great way to achieve that: You and your spouse should work together toward a mutual goal or goals that both of you care about.

It sounds deceptively simple. Yet if you're a leader, you know how motivating it is for your team at work to have specific goals and objectives to aim for. Although you should never try to manage your spouse, or treat him or her like an employee, the same dynamic is at work in every successful relationship. Having mutual goals can invigorate your marriage the same way it does your work force.

For this to work, your goals should be something outside the marriage itself. Here's why: Let's say your goal is "spending more time together." So you start tracking how much time you spend together each day or each week, working to increase those numbers of shared hours and minutes. But then what do you do during those hours? If the mere fact that you're both in the same room allows you to declare success, that's likely to be a deeply unsatisfying goal.

On the other hand, your goal could be to take the vacation of a lifetime together trekking in the Himalayas (or cruising the canals of Europe or going on safari). Working toward these goals could include researching available trips, reading books or attending presentations about your dream vacation, shopping for the things you'll need to bring, and saving and investing funds to pay for the trip. In a way the objective is the same--spending some truly wonderful time together. But the activities involved in planning for your trip give you a pleasurable future to work toward together and the satisfaction of making progress toward your goal.

Even better, working toward a mutual goal will lead you to do some of the most important things that really keep a relationship alive:

1. Communicating.

Most couples spend a surprisingly small amount of time talking to each other during the average day, especially once they've been together for a while. But if you're working together toward a mutual goal, you'll have to talk to each other to coordinate your efforts so they'll be as effective as possible. Not only that, you'll probably want to talk more, because most people enjoy talking about their goals and dreams.

2. Planning.

Making a plan together is a great thing for a couple to do. Not only does it get you talking about what's most important to you, it gets you talking and thinking about your future together. Whether or not those plans turn out exactly the way you hoped, the fact that you and your spouse or partner spent time laying out a desired future got you thinking about your time ahead together. It's a subtle way of telling each other that you intend to stay together long enough for those plans to become reality.

3. Aligning your values.

In the long run, having the same values does more to create a successful marriage than things like mutual attraction. Conflicting values can make big decisions, such as where to send children to school or when and where to buy a home very contentious. So the more you can make sure your values are in alignment--and talk constructively about those that aren't--the stronger your relationship will be.

If you think about it, working toward a mutual goal is a way of expressing what your values are. Take the example of planning for a Himalayan trek. If this is a shared goal, it's pretty clear that you and your partner both value travel, adventure, exploring new landscapes and cultures, nature, vigorous exercise, and challenging yourselves in rugged conditions. If your mutual goal is to buy a house, or get a child into an elite school, those goals reflect different sorts of values. The goals you set say a lot about what you care about so if you can set goals both of you are willing to commit to, it means at least some of your values are in sync.

4. Envisioning a better future.

The ability to imagine a better future, or at least a future in which you will be happier, safer, or more fulfilled, is a key part of setting and achieving any goal. When you and your spouse or partner set goals and work toward achieving them, you are envisioning that better future together. That will help you stay on the same page and keep your ultimate objective in sight.

5. Supporting each other when things go wrong.

Achieving any big goal means suffering through some setbacks, direction changes, and disappointments along the way. If you and your partner or spouse share these setbacks and frustrations, you can comfort each other when things go wrong and give each other the encouragement you need to keep trying even when there isn't a clear way forward. Giving each other this kind of support will help you achieve your shared goals--and you'll be more likely to give each other support at other times as well.

6. Celebrating together when things go right.

In the same way, achieving your big goal will mean having smaller accomplishments along the way. Because you're working toward these goals together, it's natural for you and your spouse to make the most of those successes, large and small. Those kinds of celebrations are a valuable element of any strong relationship. Make it a habit to mark every milestone in a festive way, and you and your partner or spouse will still be celebrating life's achievements together for decades to come.