Processing times are just estimates. Each application is evaluated on a case to case basis. Some may need more attention than others. Others may also be held up due to the third party not responding right away (e.g. banks, NBI, employers)...not the visa office's fault.
Examples where applications may take longer: if you or a family member were military or government employees, if you or a family member has been to certain countries, or if you have a namesake on a criminal watchlist, or if you have a record with the NBI.
Does any one of those apply to you, or can you think of anything about yourself that may be a cause for a country's concern?