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Applications for ACDs in call center environments include reservations centers such as hotels, auto rental agencies, and airlines. Financial institutions such as stock brokers, commodities traders, and banks make heavy use of ACDs, as do ticket agencies.

Rockwell, the company that is credited with inventing the ACD business, still is a leading manufacturer of standalone ACD systems, competing with Aspect Telecommunications, Executone, NEC, and others. PBX manufacturers such as Lucent Technologies, Nortel, and Siemens Rolm recently have captured a majority share (71% in 1995) of the ACD market [4-21] and [4-22]. Some 38,000 systems currently are installed, with the vast majority (67.2%) being in the larger line sizes (500+ lines). The market for ACDs has increased from $285 million in 1987 to $905 million in 1995, and is forecast to be over $1 billion in 1997 [4-3].

ACD Enhancements and Trends

ACDs are no longer intended only for large, isolated incoming call center applications. In response to general organizational trends towards downsizing, ACDs now are highly cost-effective in relatively small configurations. In fact, a number of manufacturers offer such a capability resident on a PC. Additionally, organizations increasingly network call centers, as well as taking advantage of agents-at-home, remoting access to the ACD and associated databases via ISDN links. Further, skills-based routing often is employed to direct the incoming caller to the most capable and available agent, whether situated in the call center or working from home [4-23].

Call-back messaging, a relatively recent enhancement, allows the incoming caller to register his desire to be called back by an agent should the caller grow weary of waiting in queue. Once the queue has been satisfied and an agent becomes available, the system will call the customer back and connect him to an agent automatically.

Call blending, another recent development, allow calls centers to improve their cost-effectiveness by serving both incoming and outgoing calling functions. Through the use of a predictive dialer, the system monitors the status of incoming calls and the level of availability of the agent pool. The system will introduce outgoing calls when it determines that the level of incoming calls has dropped to the point where the quality of the service to incoming callers will not be affected adversely. The predictive dialer will search a database of customers to be called, dial the associated telephone number, detect when the call is answered, and connect the call to an available agent. Predictive dialer software logic may be contained within the ACD, or it may reside on a PC platform with a LAN connection to the ACD [4-24].

Computer Telephony Integration (CTI)

Computer Telephony Integration (CTI) can be defined as the true blending of telecommunications switching and computer processing power. Computers have long been used to program and manage PBXs, Hybrids, and Central Office Exchanges (COs). Yet the system interfaces were proprietary and were tightly linked, with one computer associated with one set of databases and programs residing on one switching system, one voice processor, etc. This was the world of “heavy metal”, which the hardware manufacturers ruled. During this period, users received only the features the manufacturers deemed worthy and presented in the fashion they felt appropriate.

More recently, it became clear that a single computer system can control and integrate multiple telephony devices, taking advantage of the programmed (and programmable) PC’s intelligence and the realtime call processing power of the telephony switch. A PBX, ACD, and voice processor can be integrated to provide a more effective set of solutions for the processing of incoming calls. Additionally, call blending can be achieved through the application of a predictive dialer in order to improve the productivity of the call center.

While users and third-party software developers have long coveted access to PBX, ACD, and CO exchange switches, the manufacturers had no real incentive to provide it on an open basis. Claiming the risk of potential corruption of the switch databases, their real reason was more one of erosion of their very lucrative market for application software. Over time, they did allow software developers access to expensive and difficult Application Programming Interfaces (APIs) which could be used to accomplish these feats. Recently, and under pressure from end users, they opened the systems to APIs developed and standardized by various industry groups. Those APIs are available at very low cost and are much easier to use. In fact, every major PBX vendor now is shipping products that include one or more API interfaces.

The concept evolved much as did computers and their applications, in general. The field initially was dominated by IBM, DEC, and other manufacturers of very substantial hardware with the clout to garner the attention of the PBX manufacturers. More recently, PC and client/server approaches have captured the market. CTI now is available even to the great unwashed masses of small- and medium-size businesses [4-25].

At a minimum, the concept of CTI involves the use of PCs to facilitate user access to PBX and Centrex switch features (e.g., call answer, call transfer, conference calling, call hold, and call hang-up) through a GUI (Graphic User Interface) on a workstation. Taken to the contemporary extreme, the concept involves stripping the switch of much of its intelligence, which is then placed in an adjunct computer system. The adjunct computers then effectively become the PBX or Centrex switch, while the switch becomes just that—a high-performance switching matrix. Additionally, users gain access to complex information and invoke complex features through a workstation. In other words, the PBX, ACD, or Centrex system is rendered dumb, or dumber (programmable). The adjunct computer contains all of the feature content, which is capable of customization, or even further application development, by a third party or by the user organization. The applications are written by service providers in accordance with interface standards or specifications. Those applications then are uploaded to the switch, which makes procedure calls to the adjunct computer controller, as required [4-26] [4-27].


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