Singapore does not have a point-based PR system similar to countries like Canada, NZ, and Australia. You must fit the ICA's eligibility criteria for applying. However, ICA assesses your PR application based on various factors that takes into consideration multiple factors, such as duration of stay in Singapore, work pass, the highest level of education, marital status, age, etc.
Since there is no point based system, many applicants are often confused about the factors and approval rates.