DOI: 10.1007/s00291-004-0166-6OR Spectrum (2004) 26: 305

c© Springer-Verlag 2004

Editorial – Call Center Management

Call centers have become the prevalent contact points between many companies andtheir customers. Due to recent and ongoing advances in Information and Commu-nication Technology, the number and size of Call Centers, as well as the number ofpeople who are employed there or use them as customers, has grown dramatically.Efficient design and workforce scheduling/staffing are crucial for the economicsuccess of Call Centers, as labor costs typically account for two thirds of the totaloperating costs. However, efficiency goals provide a steep challenge, both theoret-ically and practically, since Call Centers face service requests that are vast in scaleand scope while customers nowadays often tolerate almost no wait. The Call Centerindustry offers numerous opportunities for the application of Operations Researchmethods.

The primary objective of this special issue of OR Spectrum is to present re-cent OR-related research contributions to Call Center Management and to examinepromising directions for future research.

Robert A. Shumsky describes a decomposition algorithm to estimate performancemeasures for a call center with two types of customers and two server categorieswhere some of the servers are specialists for one of the customers groups while theothers are generalists.

Raik Stolletz and Stefan Helber analyze a similar system with two classes of impa-tient customers and three classes of agents which are either specialists for one ofthe two customer classes or generalists.

M. Salah Aguir, Fikri Karaesmen, O. Zeynep Aksin and Fabrice Chauvet concentrateon the impact of retrials of impatient customers on call center planning and showhow to estimate real arrival rates from call center data where retrials cannot bedistinguished from first time calls.

Avi Mandelbaum and Sergey Zeltyn study both analytically and experimentally theimpact of the patience distribution on delay and abandonment in the context of theM/M/n+G queue.

Tania Jimenez and Ger Koole present results for a fluid model of a call center withtime varying parameters and temporary overload situations.

Stefan HelberKarl-Heinz Waldmann

Editors