About this work
What does the officer actually have to decide?
One thing, and the Regulations set it out. Section 179 says an officer shall issue a temporary resident visa where it is established that the applicant will leave Canada by the end of the period authorised for their stay, holds a passport, meets the requirements of the class and is not inadmissible. Paragraph (b), the leaving, is where nearly every refusal happens.
That period runs six months by default. Section 183(2) fixes it at six months or whatever other period an officer sets, having regard to the applicant's means of support, the length of stay asked for and the expiry of the travel document. The date the officer writes or stamps in the passport on arrival is what governs. The expiry date printed on the visa is a different thing: it is the last day the holder may present themselves at the border, not the last day they may stay.
None of this is a points test. The officer weighs what is in front of them. Employment, property, dependants and business at home. The purpose of the visit and whether it fits the length asked for. Money to pay for it without working. Travel history and any refusal, from any country. Conditions in the country of residence. Ties at home help an application. Ties in Canada with nothing holding the applicant at home is the pattern that gets refused.