You should definitely add Business Processes & Mapping i.e. make sure you map your processes and that there are no gaps. In addition ensure responsibilities are allocated to specific roles and that the holder of the role knows they are responsible.
Also think about embedding controls or checks within the processes designed to support compliance with relevant regulations and quality. Also consider Business Continuity Planning, you don't say if this is an internal or outsourcer call centre.
If you're an outsourcer you don't earn income when you can't operate. If it's internal then make sure that the current Business Continuity Plan gets updated.
Another critical item to look at is Management Information, what information can you get from your systems that help you manage the efficiency, performance and effectiveness of your call centre.