for migration purposes, employment is defined as "paid employment of a minimum of 20 hours per week...." Therefore you may be able to use your part time work to show the required work experience. But you need to keep in mind that this will have to be in one of the occupations listed in the "Skilled Occupation List" by the Dept of Immigration and Citizenship. As applying for permanent residency involves lot of guidelines and requirements, I suggest you thoroughly search the immigration website (
www.immi.gov.au) and/or seek advice from a registered migration agent.