Since the very beginning of our consulting business we were anxious to adapt the most recent research results to practical concerns. Over more than 20 years we had the chance to participate in findings of AT&T Bell Laboratories, IBM Watson Research Labs and several universities. One of our utmost concerns has been the architecture, installation and operation of call and contact centres. Insofar our consulting services in that field date back to the times of incumbent telecomm operators and monopolies. Several years ago we decided to give something back to the scientific community and started our own research on call centres.

From a business point of view, a call centre is an entity that combines voice and data communications technology to enable organizations to implement critical business strategies or tactics aimed at reducing costs or increasing revenues. At an organizational level, cost are highly dependent on capacity management of human and technical resources. By utilizing methods of operations research and especially of queueing theory, a suitable description in mathematical terms is to be found. A survey on queueing theoretic results geared towards the solution of problems occuring in telephony is provided arrow here. A much simpler introduction covering also relevant tools such as transforms, difference and differential equations may be downloaded from arrow here.

Current models are often restricted to a very simple set of operations, e.g. call centre agents toggle only between an idle and a talking state. It turns out, that these simplifications do not reflect reality in an appropriate way. Considering the given example, an after-call work time may be introduced following talk time. Obviously there is a high impact on capacity of system resources, because in after-call work time the agent phone is not occupied, while the agent indeed is. Accordingly a single view is not sufficient and models have to be adapted to reflect a technical (system oriented) and a (human-)resource layer. We have developed methods based on matrix exponential queueing systems, which are capable to cope with this new requirements. The final document is provided arrow here. Related computer programs are available for arrow R and as arrow Classpad 300 Library.

Furthermore we have negotiated an industry partnership, which allows for validation of the new methods in an applied setting. The results will be published as a case study in the final document. In addition to that we will develop new methods for parameter estimation in matrix exponential queueing systems. One target is to create algorithms, which are capable to estimate parameters in real-time and are ready to be implemented as part of a management information system. The models and techniques of parameter estimation will be evaluated theoretically and empirically. By combining our parameter estimation algorithms with a suitable matrix exponential model, the prediction of call centre load in real-time will become a reality also for complex configurations.

Due to personal reasons we had to cease researching call centre related topics. We have decided to publish the arrow entire work under a noncommercial Creative Commons license. On about 500 pages it covers call centre technology as well as modeling and performance analysis. All chapters except the one discussing call centre architecture in public networks are complete. As mentioned above data have been collected to support use and validation of the proposed methods in a more general setting, but the corresponding analysis has not been carried out yet. Consequently the chapter describing this field study has been omitted completely. We had the hope to provide a holistic and complete document on call centres, where topics are put in context instead of being issued in the form of unrelated scientific papers. In releasing it to the public we hope, that researchers will carry on what we have started.

Occasionally we will also publish documents, which do not relate to traffic engineering of call centres. These will be found in the arrow resources section only, so it may be worth a visit.

@2019 .Telecomm