evice, another location or callers may just hear ringing. The Telecom Handbook * 79 THE ACD DEFLECTION The cost of calls to an 800 number mounts rapidly as callers wait for an agent to answer. To decrease the cost of callers waiting in queue for an answer, deflection decreases hold times by having callers reach a busy signal or by rout- ing the calls to another destination. This happens when the system recognizes that a management-defined threshold has been reached. Deflection is typically based on the number of calls in queue. A more effective parameter offered by some systems is "time in queue." In this case, a caller receives a busy signal when the longest call in queue has been in queue over "X" minutes or seconds as defined by management. INTERFLOW This provides automatic transparent traffic rerouting based on predefined times/days or traffic thresholds. This is useful for multi-site Call Center networks where call volumes and hold times may be high in one location while there is idle time at another location. Or a business may span several time zones and man- agement may want to avoid overtime in one zone by routing calls to another location. Interflow helps Call Centers attain optimum agent productivity while controlling toll costs. Performance Measurement To be successful, Call Center management must set perfor- mance objectives, and then measure performance against these parameters. Real time displays and historical reports should show actual performance as compared to these criteria. A list of per- formance objectives might include average: Time to answer Talk time Hold time Work time Idle time Time in queue 80 The Telecom Handbook CHAPTER 4 Agent Capabilities Sign-On/Off Agents may serve more than one group and may rotate among several workstations during a shift or during a week. In order to monitor and evaluate agent performance, it is impor- tant to be able to track which agent is at which telephone. Each time agents make a change, they are asked to sign on and sign off the group they are serving. A