Found some good info in one of the forums:
Reasons for delay during background check:
This is the bulk of your processing time. So, naturally, the more straightforward your application is, the faster it is going to be processed. If something is not clear, wrong, etc, and we will talk about that later, it will cause delays.
Background related factors:
- The number of dependents: This has been reported to affect your application, especially if your kids are older. For spouses, the same principle applies, the easier it is to check on the other applicants, the faster it will be.
- The country you were born in: Because the security background check depends on external security agencies and partners, the diplomatic relationship between your country and Canada will affect this. If your country is in good diplomatic relationship with Canada, it will be faster. If not, they will have to use other means to confirm you are not a criminal. They will basically spy on you.
- The country you were born in again: Your application is analyzed by specialists for a cluster/region. That means they speak your language, know your government website addresses, know how things look like, fake website addresses, universities that do not exist, companies and cities. They know everything. That means that, to have those specialists available, that will depend on how many applicants from that region CIC is getting, in other words, if they have 3 employees, the processing time will change if they take 300 or 1000 application per month, plus, how easy it is to verify that information for everyone, meaning, people with delayed applications will cause a delay for everyone. The problems for that country or cluster of countries will be a common problem for everyone in the cluster. That doesn't mean that, if your country get fewer applicants (let's say you are from Monaco, San Marino or the Maldives) it will be faster, because they will probably also have fewer employees or third parties of that cluster since they don't pay for people to do nothing. According to the immitracker, the paper-based inland applicants getting the fastest MR were from USA, China, Korea, Ukraine, and India. If you have been to Canada, I believe it will be quite obvious that Indians and Chinese applicants are not few. Despite that, their applications were going somehow faster, probably because they have more specialists.
- How tech savvy is your government: If you police certificates can be checked online, if they have a barcode that the CIC agent can use to confirm the veracity of the information you provide by going to the federal police of your country and check that your police certificate is original, it is faster.
- Previous jobs: How easy they can verify will affect your time. If they can easily verify the companies you worked with exist, or that your number of years of experience are accurate
- Education: If your university is a big and good one, it is easy to check, because they have a good online presence. In some of them, the diplomas come with a code, and this code can be used online to check if your diploma/certificate is original. That speeds things up a bit.
- Involvement with the army: If you were male, 18, had to go to the mandatory army and then left, you show this document and that is it. But if you were a Sargeant, then your application processing time will obviously change if you were a Sargeant with the US or UK armies, or if you were Sargeant in Iraq, Russia, or North Korea.
- Religion: Well, sad to say, but it will change if you are a Muslim. Everybody knows that but nobody wants to talk about it. It is the big white elephant in the room. It will never show up in nobody's GCMS notes.
- Past involvement with drugs: Do you smoke pot? If you do, you probably bought it from the narcotraffic. That means you know some stuff and somehow contributed to the proceedings of the crime because drug dealers don't simply sell recreation. They destroy families. It may delay your application. Although alcohol is also a legal drug and cigarettes are as bad as pot, you should consider quitting everything. It is bad for you.
- Criminal background, criminal activities, general activism, political involvement: If you have a criminal past, please, don't go to Canada. Now, if you were unfairly jailed for a day or went to the station because you were protesting for a transgender thing, free education, whatever, and there was a clash with the police, you were young and stupid, don't try to hide it in your application. If you got a dangerous driving ticket, or even if you punched someone in self-defense, don't hide anything. Anything hidden will severely delay your application.
Now with that said:
-Countries were you live and worked in: Everything said above will apply to each country. I believe it is done simultaneously, so the slower country will be the culprit for your processing time, but I have seen people that live in too many countries having longer processing times.
-Dependents and applicants: Everything said above will apply to each dependent. Unless they are 4 years old.
-Past employment and additional document requests, travels (schedule A): If you change anything that belongs to your background, you have to update them.
