A CIC agent assigned to verify your application prepares a report for the immigration officer, if all is well he/she puts a lable as "Recommended Pass" on your file before sending it of to higher authority, it means he/she has thoroughly verified all documents supplied by you to support your case and according to him/her your file is clear for approval, chief officer then goes through this file and puts in a final decision, very very rarely a chief officer can ask for further proof or doubts the decision of their agents, in final security check (Background check) they verify which is your country of domicile, and all the countries that you have visited, basically if they are safe or not, if unfortunately you have visited some of the unsafe countries, then your file takes considerable time to get a clear signal. Wish you good luck for much awaited PPR.