How to get permanent residency in Sweden is relatively easy. There are quite a few permits that can lead to permanent residence. Generally, you just need to spend enough time on one of the following permits. Some of these are:
Time spent in Sweden on a student permit or on a working holiday visa does not generally count towards the time needed for permanent residence.
Standard work permit, EU blue card, guest researcher, and doctoral students
The process for obtaining permanent residence as someone holding a standard work permit, EU blue card, guest researcher, and doctoral student are relatively similar. In order to obtain permanent residence the core requirement is to have held a permit for a combined period of 4 years in Sweden (excluding time spent on student permits) during the past 7 years. The assessment of permanent residence will be made in conjunction with the extension application that is submitted. The case officer should automatically make the assessment and see if permanent residence can be granted.
ICT permits can lead to permanent residence but the path is a bit unclear at this time. As with the other permits mentioned above, permanent residence can first be granted after the individual has held a permit for 4 years. ICT permits can, however, only be granted for a maximum combined period of 3 years (2 years for the initial permit + 1 year for the extension). After a person has held a permit for 3 years it is assumed that they must leave Sweden and apply for a new permit again from abroad. As the ICT permit is relatively new, nobody has held a permit for 4 years yet so it is unclear how this process will be handled.
For dependents, the process is a bit different. Permanent residence for dependents can only be granted either in conjunction with the main applicant being granted permanent residence (if the applications were submitted together) or if the main applicant/reference person in Sweden already has permanent residence. They cannot be granted permanent residence on their own merits as a dependent and require the main application to be granted this first.