ow familiar recorded announce- ment, "All representatives are busy with other customers, your call will be answered by the next available representative." Characteristics that distinguish an ACD from a regular PBX are: Calls are answered by the representative who was idle the longest. The call volume and workload can be monitored in real-time. Callers are queued up and answered in the order that they are received. Statistics are available on the level of customer service pro- vided and the productivity of the representatives answering the calls. Most business telephone systems are designed to have more telephones than outside lines, the assumption being that not everybody is going to be on the telephone at the same time. For example, you may have 100 people sharing 25 outside lines. In an ACD environment, it may be just the opposite. A smaller group of people handle a greater number of lines, assuming that callers will wait for some period of time for the "next available representative." With an ACD, 25 The Telecom Handbook 75 THE ACD people may be handling 100 outside lines. This affects the system components and software, distinguishing an ACD from a regular PBX. As with PBXs, every ACD works in a different way. No two are exactly alike. Some companies manufacture telephone systems to work specifically as an ACD and not as a regular office telephone sys- tem. Their systems are known as stand-alone ACDs. Most other PBX manufacturers have ACD capabilities that may be purchased as an option, at considerable additional cost (can add 50% to 100% to the price). A PBX can be set up to work exclusively as an ACD. You may also have an ACD as a sub- system of an office PBX, but not have all telephones working in the ACD environment. The Collins Division of Rockwell pioneered the ACD in the early 1970's with an installation at Continental Airlines and later at Pan Am and United Airlines. The system evenly distributed large volumes of incoming calls for reservations and ticketing. This bit of history was contributed by Pau