In my opinion, before COVID-19 it used to follow this pattern:
a. AOR - 3 to 4 months after submission
b. ADR follows within 2months after completion check.
c. AIP ( I am almost certain background check via name search /open source, FOSS check and other internal methods , is done before AIP) in a nutshell, Eligibility will not start unless background check is pass
d. The next stage is Security and Criminality checks which can take between 4months - 1year, depending on the so many factors which may include situations in the country of origin, speed in verification of supporting documents etc. Once this stage is pass, you get a DM. Then you will be told to await finalization from Etobicoke, Ottawa, Alberta as the case may be, usually within 2months for a brief interview and COPR.Then you will be asked to submit 2 passports and apply for the PR card. If you have dependants outland, you will be asked to submit their application at a regional offices for processing ( this may take 4 - 6months). I maybe wrong, this is what Iearn from reading online.
However, since COVID-19, a lots has changed. They seem to have merged AOR/ADR/Background checks. That's the reason why people now can see medical received, AIP, even DM shortly after receiving AOR ( as you all know AOR takes 11 months to 14months, except for those who qualify for Concurrent application/Fast track).
IRCC is really doing a very remarkable job irrespective of the delay in AOR, this new method seem fast. Once you get it.... Everything changes.
Let's keep on encouraging one another and hope for a speedy resolution of our applications.