For example, an SW1 applicant would be eligible under the MI if they had 7 months of full-time (or equivalent) work experience in NOC 6242 immediately followed by 10 months full-time (or equivalent) work experience in NOC 6241 in the last 10 years. Experience accumulated in each NOC counts towards calculating one year of continuous experience. It is not necessary for the NOCs to be in related occupations, as long as all NOCs are listed in the Ministerial Instructions.
Previous instructions that an applicant cannot make up the one year of continuous full-time employment experience in a series of continuous periods of employment in different occupations that total one year are revoked (see OB 93 – question 5, OB 101 – question 5).
http://www.cic.gc.ca/english/resources/manuals/bulletins/2010/ob173.asp