Hi there,
Hmm, good question... but generally it's not as straight-forward as that.... schools prefer students to have some good work experience so that they contribute to classroom discussions, and a lot of learning at b-school comes from your classmates, not just the professor or curriculum... so hence the need for a variety of industries, experiences, skills, etc to be present in those classrooms! Most schools don't make it a hard and fast REQUIREMENT per se, so you may find that technically most schools allow fewer than 3 years... but do they accept many of those??? That is the question, and generally the answer is no or very few. Especially at top programs. The further you look outside the top 25 or so, the easier it is to get in with less than average experience. But again schools may say-- get some additional life/work experience and THEN apply... just something to consider. You can certainly get in touch with specific schools to ask their opinion, and you can tell a lot from viewing the online class profiles too. Good luck!