A recent inquiry of IRCC about the questionably, long processing time for self-employed applications resulted in the following official response by the department:
We can confirm that the processing times posted on IRCC’s website for the Self-Employed Persons Class are correct. The large discrepancy between the processing times over the last year is due to a change in the way that processing times are now calculated. Prior to December 31, 2015, processing times were displayed by visa office, which was useful when applications were always processed by the nearest visa office. However, we now have the ability to move applications around our global network to ensure they are processed as efficiently as possible. As such, we now display a single processing time for each line of business, which is updated on a weekly basis. For the Self-Employed Persons Class in particular, the single processing time is greatly skewed by a large backlog in one of our visa offices. However, once the aging backlog is exhausted, processing times should drop back down quickly.