As the saying goes, don't quit your day job. 

Launching a part-time business can be just as rewarding—and potentially as profitable—as full-time entrepreneurship. It can also reduce many of the financial risks associated with entrepreneurship while you continue to generate income and maintain the benefits from your full-time job.

"Chicken entrepreneurship," as Michael Masterson puts it in his book Seven Years to Seven Figures, is becoming an increasingly popular, and feasible, way to start your business. "I think there are thousands and thousands of potential chicken entrepreneurs out there in the world, dreaming of quitting their jobs and starting their own businesses, but afraid to do so," he wrote in a recent article.  Running a part-time business comes with its own set of challenges, so you need to be prepared for the road ahead before launching. Whether you're just looking to generate some extra cash on the side, or you plan to transition your part-time business into your full-time gig, here are a few tips on how to create a successful part-time business strategy.

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Running a Part-Time Business: Understand Your Investment

The first thing you must define is what exactly "part-time" means to you. Is it 10 hours per week? Fifteen hours? Thirty hours? If you're working a full-time job, it's especially important to know what you're getting yourself into, so that you don't burn out while working nights and weekends.

Craig Jennings, the president of Powhatan Coaching, an entrepreneur-coaching service based in Long Island, New York, says the first thing any entrepreneur must do is to create what he calls a "success plan." This document should elucidate your goals and expectations for the part-time business. Jennings, himself a serial entrepreneur who has launched eight companies, says it's critical to write down exactly how many hours each week you plan to work on your business.  "What's critical is that when you set out to do this, you don't just say you're going to 'try hard,'" he says.  "As Yoda says, 'there is no try,' you either do it or you don't." 

The initial document should spell out a list of milestones, and what you plan to achieve in your new part-time venture. Think about how much you're wiling to sacrifice for the business, and what kinds of returns you expect to see. Ed Gandia, who launched his copywriting business part-time, says he broke down his goals into yearly and monthly milestones, but that he underestimated how long—and how difficult—it was to launch the business while working a full-time corporate sales job. "It took more energy—emotional energy—out of me than I thought," he says.  The advice he now gives to fellow entrepreneurs is to "figure out what you think it's going to take…then write that down and then double it."

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Running a Part-Time Business: Get Support From Family and Friends

Launching a part-time business can put strains on you and your family. After all, your family will want to know what you're doing, why you're doing it, and how it will affect your life. Often, starting and running a business part-time will mean that you're working nights and weekends, which can hurt relationships with a spouse or children if they're not on board for the experience.

Besides for discussing your plans with family members, a great way to alleviate some of the stress is to involve your family members in the process. Ginger O'hara, the founder of Serendipity - Beyond Design, an invitation design firm based in St. Louis, Missouri, says without her family's support, she never would have been able to take her part-time business to full-time. O'hara says her husband was encouraging while she worked nights and weekends on her business, and even helped her take packages to the post office. Ohara's sister, who lived with her at the time, would help glue crystals and tie ribbon. "You need to have that support group," O'hara says.

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Running a Part-Time Business: Manage Your Time Effectively

The importance of managing your time is amplified when running a part-time business. Clients will want to work with you on their schedule, not yours. Working part-time can present several logistical challenges, so having a carefully managed calendar is critical for success.

Ed Gandia, for example, says he needed to become extraordinarily disciplined about scheduling for his part-time copywriting business. "I woke up earlier in the morning and went to bed later," he says. On Saturdays, he'd work from 6 a.m. until 12 p.m. so that he'd have time to spend with his family. Without precise scheduling, he says, the business would not have become nearly as successful. "Scheduling is definitely the key," he says. Take advantage of time management apps like Remember the Milk, which lets you sort your tasks by urgency and due date, as well as send reminders to yourself via text or e-mail.

A major concern among part-time business owners is responding to the needs of clients in a timely manner. If you're at work, you may not be able to answer calls or respond to e-mails as quickly as a full-time business.

But there are ways around this. Google Voice is one of the most popular apps for part-time and home-based entrepreneurs, since it allows users to "open" and "close" their business as they please. It also forwards voicemails to you as a text, so you can see how quickly you need to respond to someone.  Virtual answering services, like Reception HQ, based in Phoenix, offer professional phone-answering services for a modest monthly fee. This way, someone will always be answering your phone, explain that you're unavailable at the moment, and take a message.

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Running a Part-Time Business: Get a Coach

While a part-time business reduces the financial and social risks of entrepreneurship, it also sets the most dangerous risk of all: procrastination. Working a full-time job can be extremely taxing, so it's easy to drag your feet when it comes to a part-time venture, whether it's expanding your clientele, improving your services, or marketing the business. This is especially true when you haven't invested too much money into the business. In other words, low-risk can mean low-rewards, and it's easy to become lazy about promoting your business.

"The problem is, we're liars," says Jennings. "If we say 'I'll give it ten weeks,' then you say 'well I really meant 15.' At the end of 10 weeks, you need to ask yourself what you've gotten."

The best way to combat this common problem is to develop a relationship with a someone Jennings calls an "accountability partner." This person can be anyone; a paid coach, your spouse, a friend, or even your next-door neighbor. Many of us dream of not having a boss, but sometimes having someone to report to is necessary for business to get done. "Find somebody that you can work with and bounce ideas off of, where you can have a regular conversation, even if it's over a couple of beers," Jennings says. "You need someone to hold your feet to the fire."

When looking for an accountability partner, choose someone whose business acumen you trust. You'll want to be able to talk over various parts of your business, and let them know what you plan to accomplish—and when you expect to reach those goals. The right person will be able to see the holes in your business model, and point you in the right direction. "When you discovered you screwed up, you can change course," Jennings says. "But if you never discover it, where are you?"

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Running a Part-Time Business: Embrace Your Failures

Thomas Edison liked to joke that there were 1,000 ways he knew how to make a light bulb that did NOT work. Part-time entrepreneurship sometimes feel similar, and that's why it's important to embrace your failures and learn from your mistakes.

For example, it took Ed Gandia nearly six months before landing his first customer. His mistake? He didn't leverage his background in sales and marketing to attract customers. After working with a coach, he realized that his experience in the sales field was actually a great addition to his business. Once he made the change to his site, the phone started ringing. "My business changed overnight," he says.  "People were now paying attention and not balking at my fees."

Part-time business owners tend to learn more from their failures than they do from their successes, according to Jennings, who continues to run three of his businesses simultaneously. "Failure is not only an option," he says. "It is the entrepreneur's on-the-job training."