complete 15 missions from external groups which are:
- Chanter's Boards
- Favors for Certain Interested Parties
- The Mage's Collective
- The Blackstone Irregulars
once the 15th mission is the quest is completed the achievement should pop up,
If you are having trouble with the quests go to the external site below,
http://dragonage.wikia.com/wiki/Job_Board