Developing a Business Model That WorksUse these six tips to create the financial section of a business plan that will get your company off the ground.

The following excerpt is fromScott Duffy's bookBreakthrough.Buy it now fromAmazon|Barnes & Noble|iBooks|IndieBound

What's the first step in figuring out how to execute your big idea? Creating a working model for your business.

We've all been brainwashed into thinking that the best way to do this is to sit behind our desks and write a long, detailed business plan. You know the kind: It starts with a fancy cover and your mission statement, then describes your team, market, product, competition, and so on.

Most entrepreneurs spend a lot of time and resources writing their plan. Too often, they get feedback from all the wrong people. Their friends and family want to support them, but they're telling the entrepreneurs only what they want to hear—that they have come up with the next Google or Apple or Tesla (keep in mind, none of this feedback is coming from customers). By the time the entrepreneur gets to the last section in the business plan—the financials—he's totally sold on the idea. Sometimes the financial section is left unfinished or dropped entirely as the business is launched.

And why not? We're passionate. We're committed. We know we can't fail. So what are we waiting for? Let's go!

Here's the problem: Most entrepreneurs change their business model six times when working through the financial section of their plans. While running the numbers, they identify key distinctions with regard to income and expenses. They gain a deeper understanding of what it will take to break even and how to achieve free cash flow. As a result, they come up with better-informed strategies for attaining their desired financial outcomes.

The most important part of the initial business planning process, and the one people most often neglect, is getting your numbers to tell a story that makes sense for you and your investors. If you start at the beginning of the plan only to learn that your assumptions about the business don't add up once you reach the end, you've lost valuable time and money.

Regardless of whether you're in startup or growth mode or moving to the next stage of your business, mistakes can be costly, so here's what I recommend:

1. Start with the last page first.Once I have a basic understanding of what I'd like to build, the market, my target customers, the business opportunity, and the product, I dig right into the numbers and create a simple one-page spreadsheet that clearly identifies how the money flows. Basically, I write business plans backward. I've learned that once the numbers tell the story you want, the rest of the plan will write itself.

2. Don't wait.Don't make this process more difficult than it needs to be. Limit your model to one page. Create the simplest, most basic spreadsheet you can that identifies income, expenses, breakeven, cash flow, and the capital required to achieve your outcome. Use conservative assumptions, and don't rely on best-case scenarios.

3. Get out of the office.You'll learn more about your business by getting into the market than you ever will sitting behind a desk. At least 50 percent of your time should be outside the office gathering information that can be applied to your plan. That means contacting industry insiders to learn more about the market, talking to prospective customers about their needs, and testing your competition's products and services.

4. Be careful who you listen to.When we have an idea we passionately believe in, we're convincing. It's easy for our family and friends to tell us we have a winner on our hands because they want to be supportive. But when you're modeling your business, the people whose feedback matters most are current and potential customers. Listen to what they have to say and apply what you learn to your model. Let their feedback, and not your enthusiasm, sway your projections.

5. Don't throw out negative feedback.Sometimes it can be difficult to absorb negative feedback in a constructive frame of mind because we're so close to our projects and have so much on the line. We start rejecting and deflecting feedback that isn't in line with what we believe. But honest, educated feedback is like gold—use it to open your mind and ask tough questions about your assumptions. You must be obsessively committed to asking what you can learn from this feedback and how you can apply it.

This is especially important for people entering new markets where they don't have prior experience. Getting feedback from others who've lived in the space will add to your perspective. Sometimes you'll learn that there are things you don't know as a newcomer that would significantly impact your financial results. In fact, this holds true throughout your business's lifetime. The entrepreneurs I know who've built the most successful and thriving businesses are obsessed with getting constant feedback from the marketplace and adapting their businesses based on evolving market needs.

6. Be open to what the numbers tell you.The worst thing you can do is try to manipulate a model to match your assumptions. You need to approach your financial model with a completely open mind. Recognize that it will probably take longer than you initially thought to get to market, generate revenue, create profits, and accumulate the cash flow you need to operate and further invest in the business. By being open, you'll be able to make distinctions, apply them to your business, and set yourself on a path to success.

You need to be clear on where you want to go and put a simple and adaptable plan in place to help you get there. The clearer your vision is upfront, the easier it will be to back a plan to help you get there. Being obsessed with customer feedback will enable you to tweak strategy in a way that evolves with the market and helps keep you on top of the competition.