Jane Versalovic calls herself "the poster child for flexible work arrangements." A senior manager at a major accounting firm in Boston and a mom to two grade-schoolers, she's tried it all--full-time, no-time, and part-time. She loves being a mom but "work is a huge part of who I am," she says. "I can't imagine completely dropping out." Currently a one-day-a-week arrangement works great for her.

Jane is just one of nearly six million mothers in America who work part-time. Money used to be the main reason moms worked, but now it's likely they're looking for the same thing Jane is. "They want to find great balance and continue in their profession," says Kirsten Ross of womans-work.com, a website that helps women find alternative work arrangements.

While it may sound like an ideal arrangement, those who work part-time walk the same tightrope that all working mothers walk, all the while balancing the weights of work, family, and self. Those weights may be more unwieldy for part-timers, in fact, than for people who work full time: because they don't feel as justified delegating stuff at home, they often end up doing more.

Furthermore, when the "extra" time they envisioned never materializes, the perceived risk to career advancement doesn't seem worth the tradeoff. What looked like it was going to be the best of both worlds suddenly becomes the worst.

It doesn't have to be that way. Assuming you've done the math and it's financially feasible to work part-time, working part-time can be a fine answer to the question of work/life balance. You can avoid most of the pitfalls that come with moving to part-time by being explicit about your own expectations--and by making sure that everyone else is being explicit about theirs.

Find a supportive boss

Maybe you work simply for the challenge, or so that you won't lose professional ground. Maybe you're one of nearly a third of part-timers who expect to be promoted. Either way, it's important that your expectations match your employer's.

Versalovic suggests starting with your boss. "The organization's support is just the foundation," she says. "I'd choose a job with a boss who truly 'gets it' any day." She considers her supervisor another partner in the arrangement, and their mutual trust, respect, and flexibility make it work.

Indeed, a study conducted by Catalyst, a New-York based research organization, found that one of the main obstacles part-timers run into is resistance from managers who "may bear extra burdens because of unclear policies and practices."

So clear things up. Talk with your boss about expectations--yours, hers, your company's. If you're hoping to work a day from home, ask the company's stance on telecommuting. If advancement is important to you, ask if she will support your goals within a part-time arrangement.

It's especially important to talk about how willing she and you are to be flexible with the part-time schedule. Kitra Howley has two children and works three days a week as a private banking assistant in a large mid-west bank. She willingly picks up an occasional Monday when asked and scrambles to attend important meetings that fall on days that she wouldn't normally work.

But she safeguarded her family time by requesting that she would never have to work on Fridays and that she would always be able to depart by 3:00 on Thursdays. It's a mutual cooperation that has cemented her commitment to her employer and allowed more time dedicated to her family.

Be explicit on the home front

Wanting more time for family is the reason most people move to part-time. But people don't always end up spending that time the way they envisioned. Susan Chira, author of A Mother's Place (HarperCollins 1998), claims women working part-time often still take full responsibility for child care and household management. "As a result, they could end up feeling more stress than full-time workers, who would delegate more of those tasks," she says.

More chores? More stress? This may not be exactly what you have in mind.

You've had the difficult conversation about expectations with your boss; now it's time to have the same one with your partner and children. Get specific! Because you have more time, will family members expect that you'll do the lion's share of cooking, cleaning, and car-pooling? More importantly, will you expect it of yourself? There's nothing wrong with that, as long as it's what you want.

But if you have visions of using the extra time to make paper airplanes, paper hats, and paper mache' solar systems with your children, be explicit with family members about your reasons for wanting to work part-time. Tell them you want to spend more time with them, not with the vacuum. Then ask for their help.

What? No volunteers? Make assignments, and deem Saturdays from 9-12 as team cleaning days. This would also be a good time to evaluate your cleaning standards. Balanced perfectionist? Oxymoron. Decide on the things that you can let go (most likely the same things you let go when you worked full time), and then let them go.

Also, don't expect that switching to part-time will clear up childcare glitches. When your child gets sick--and she will--on a day that you work, who will stay home? "My husband usually stays home when the kids are sick," Howley says. Their logic: she's got fewer days to do her job, so it makes more sense for him to take off.

Agree on what criteria you'll use to decide. If you can't agree on criteria, then at least agree on whether you'll use coin-flipping or rock/scissors/paper as your decision-making tool.

Carve out time for yourself

Regardless of whether they work outside the home full-time, part-time, or not at all, most moms find it hard to take time for themselves. "Relaxation" leaves their vocabularies about the time breast milk comes in. But if you're feeling out of whack, how will you balance everything else?

Relaxation takes as many forms as there are mothers. Versalovic runs. Howley meets friends for dinner. Read a book without "success" or "child" in the title. Take a photography class; take in a movie; take up yoga.

It's particularly important to arrange regular dates with your husband, even if it means sharing Tuna Delight at your kitchen table once the kids are in bed. You'll need this time to talk to each other about this balancing act you're in together.

Your expectations will evolve--for work, home, and yourself. Assess. If it's working, great. If it isn't, take advantage of your choices, as Versalovic does. You can move from part-time to flex-time to no-time. You might work out of your home or go full-time. Your steps will be steadier if you're meeting your own realistic expectations--and if you're happy doing it.

That's how Howley knows she's on the right track. "I have a smile on my face when I go into work and a smile on my face on my way home," she says. "It's just bigger on my way home."

MARY PETERS has almost taken up yoga twice. She figures this is her year.