Hi WeAreThe11,
There are multiple variables/factors play into the assessment of an application. Hence, the Red Flags would be more.
Complexity of the case - Need not to say if the case is not straight forward it takes more time.
Application is not clear - How good the narrations in the application are, and how understandable by assigned officer.
Travel History - It makes lot of difference. Trips to Canada need additonal back ground checks. Working and Living in some specific countries (red flaged countries) will add more time.
Changes in family - Births/Deaths of parents/children/siblings etc sponsor/sponsored etc will increase timeline. Someone rediculed for having a PCC for an infant. But I read news in internet more than one time about infant thefts from hospitals.
Work history of Sponsored Person - working with governments/UN - if sponsored person worked for foreign government (including country of birth, India) would require more security checks.
Current Job of Sponsor - If sponsor is working for crown corporations and/or governments (Fed/Prov) the spousal background is done during the process time.
Medical concerns - If medical board suggests remedical to ensure no active health concerns. Please note not only the expiry date will warrant a remedical but any health concern would trigger the process.
Need for interview - If an interview is recommended the schedule will add more time.
The above are a few factors but many more will come into play during processing and assessing an application. I hope this helps a bit.
Cheers.