Agent availability is the amount of time that agents are available and waiting to take customer calls. It is usually expressed in terms of a percentage. The professionals of the call center handle both incoming and outgoing customer calls in relation to business. Agents adroitly handle account inquiries, customer complaints or support issues. Other names of outsourced call center representatives are customer service representative (CSR), telephone sales or service representative (TSR), attendant, associate, operator, account executive or team member.