Ideally, it’s also more than just a one-off document. Smart business owners pull their business plans from the drawer (more likely, the hard drive) every so often to recalibrate where they stand in relation to the original vision.

To get started writing yours, fire up your high-speed Internet connection. A quick search under a phrase like “how to write a business plan” leads to plenty of solid advice about writing (or rewriting) your business magna carta. One resource we’ve found especially helpful comes from the U.S. Small Business Administration, which walks newcomers through the process of writing either a traditional plan or a higher-level “lean” business plan.

Either way, there’s a possibility of getting ambushed by what seems to be an innocent-enough element of your business plan: a mission statement. An effective, purposeful mission statement can be vexing even for the savviest small business entrepreneur.

Why so?

Often, it’s because it’s easy to mistake a “mission statement” as a broader version of a profit-and-loss statement. In other words, it can be tempting to stray from the idea of purpose -- the defining reason a business is here on this earth -- and talk more about financial outcomes from the start.

It’s not that profit doesn’t matter; of course it does. Profitable businesses stay in business. Unprofitable businesses, not so much.

But a helpful tip in drafting your mission statement is to draw back the lens and consider things from the outside in: the vantage point of your customers, not your inner accountant. In other words, knowing that making a profit is the intention:

• How will your business get there?
• What essential contribution are you proposing to make to your target market?

Let’s put it in terms of a hard example. Here are two ways to think about the mission statement of a newly established laundry service (we’ll call it “Launderific”) on the south side of town.

Sounds great, yes? Well: sort of. The above statement describes what our business is, in terms of core competencies and services. It talks about what we aim to do, and how we aim to do it. But it falls short of providing a greater sense of purpose and resolve. What’s more, it tells our story from the inside out, not the other way around.

Here’s another approach that reminds us why people won’t merely be willing to do business with us but will go out of their way to do business with us. Here, our core offering isn’t a clean shirt. It’s the idea of delight.