External change agents are hired to fulfill a specific function or role for a specified period. The external change agent’s role is determined by the change manager and is typically outlined in a contract. The contract should specify the exact nature of the work to be performed, the timetable for the work, length of service, method and amount of payment, and some way of evaluating the change agent’s performance. Some organizations negotiate a performance clause, which gives the organization the right to evaluate the change agent’s efforts at any time and provides that the contract can be terminated if the work is not up to the agreed-upon standards.