"I've always dreamed of starting my own business." "I'm tired of working for someone else."

As mentors for women in the IT field, we often hear these comments from proteges who are tempted to start their own companies. But many of these women become overwhelmed by all the unknowns in creating their own businesses. Starting your own firm is like being one of the first passengers on a transatlantic flight. Will you make it across? What will you do if the plane goes down?

Before you move from your secure position at an established company to start your own business, it's important to evaluate the environment that your current employer offers and assess whether you really can go it alone.

Support Structure

A large company: Established companies have bureaucracies in varying degrees. But while bureaucracy can be viewed as an impediment to getting things done, the structure a large organization provides can also present an enormous advantage. When you tackle a new project or launch a program in a large company, a support structure is typically in place that fills all the marketing, finance and legal roles -- areas in which you may lack expertise.

Your own company: You're not just an IT consultant. You're the sales representative, Web designer, accountant and HR person rolled into one. Be prepared to be an expert in your own field and well versed in the operations of a company. The transition from the singular responsibility of a job at a company to being the company will seem unsettling at first. Take the time to become accustomed to accepting full responsibility for everything that happens.

Deep or Broad Expertise

A large company: Corporations generally give employees an opportunity to become much more specialized in their field and cultivate their skills at a greater depth through professional development. You can attend professional seminars and classes and join professional organizations, often at the company's expense.

Your own company: In contrast, starting your own firm gives you an opportunity to learn everything you ever wanted to know about the operations of a business. Matters such as paying the bills, becoming a corporation and building a Web site all become the assignment of the entrepreneur. These tasks need to happen but can detract from the development of your main skill set and the primary goal, revenue generation.

Missing the Crowd

A large company: After you've worked for companies all your life, you can get lulled into a sense of comfort by the camaraderie that exists among your co-workers. Sometimes it's nice just to have someone to talk to during the workday. From a career perspective, co-workers and managers are resources you can learn from and collaborate with. When you branch out on your own, it can sometimes be a lonely struggle if you don't have a support network already in place.

Your own company: Building a network of support can be critical to your success. Make sure you take advantage of outside resources designed to help small businesses, such as the NSW Department of State and Regional Development . Finding experienced mentors and/or business associates who can help and truly want to assist in your growth can mean the difference between success and failure. You should also look into industry or shared-interest groups to build a support network, and identify mentors to help you through the process.

Company Brand

A large company: Your employer has likely spent years and millions of dollars building its brand. When you work for an established company, that brand rubs off on your identity. When you say, "I'm a manager at FedEx," the person you're speaking to has a better sense of who you are, based on the company name. Employees derive a sense of comfort and credibility from the companies for which they work.

Your own company: You are the company. Nowhere is it more important to have your own brand than when you're working for yourself. Particularly during the start-up phase, prepare to be bold and certain about bringing your own credentials to the table and answering the question, "Why you vs. someone else?" The discussions you may be involved in no longer will be about the company you work for but about what you can do for potential clients. At the same time, starting your own business gives you the opportunity to begin from scratch and define what you want the company to be known for, stand for and work for.

And since everything that happens to the company essentially happens to you, be prepared to work much longer hours. Enthusiasm, not to mention sleep, often runs out in the short term, so make sure you have firm convictions and that you're personally and financially prepared for the long haul.

Is it all worth it? If you're one of those rare individuals with the vision and initiative who enjoys challenges and risks -- and the benefits they bring -- it can be the experience of a lifetime.

Mary Ann Wagner and Marguerete Luter are frequent contributors to Computerworld.com and co-chair Women in Technology's Mentor-Protege Program. Alexandra, Va.-based Women in Technology is a not-for-profit organization dedicated to offering women involved in all levels of the technology industry a wide range of professional development and networking opportunities. Wagner is president and founder of XIO Strategies, and Luter is vice president of global bid management at Unisys Corp. Contact Mary Ann Wagner at mwagner@xiostrategies.com and Marguerete Luter at marguerete.luter@unisys.com.