A multi-server queueing system with two types of customers and an infinite buffer operating in a random environment as a model of a contact center is investigated. The arrival flow of customers is described by a marked Markovian arrival process. Type 1 customers have a non-preemptive priority over type 2 customers and can leave the buffer due to a lack of service. The service times of different type customers have a phase-type distribution with different parameters. To facilitate the investigation of the system we use a generalized phase-type service time distribution. The criterion of ergodicity for a multi-dimensional Markov chain describing the behavior of the system and the algorithm for computation of its steady-state distribution are outlined. Some key performance measures are calculated. The Laplace-Stieltjes transforms of the sojourn and waiting time distributions of priority and non-priority customers are derived. A numerical example illustrating the importance of taking into account the correlation in the arrival process is presented.
Department of Applied Mathematics and Computer Science, Belarusian State University, 4, Nezavisimosti Ave., Minsk, 220030, Belarus
Bibliografia
Aksin, O., Armony, M. and Mehrotra, V. (2007). The modern call centers: A multi-disciplinary perspective on operations management research, Production and Operation Management 16(6): 655-688.
Al-Begain, K., Dudin, A., Kazimirsky, A. and Yerima, S. (2009). Investigation of the M₂/G₂/1/∞, N queue with restricted admission of priority customers and its application to HSDPA mobile systems, Computer Networks 53(6): 1186-1201.
Al-Begain, K., Dudin, A. and Mushko, V. (2006). Novel queueing model for multimedia over downlink in 3.5g wireless network, Journal of Communication Software and Systems 2(2): 68-80.
Chakravarthy, S. (2001). The batch Markovian arrival process: A review and future work, in A. Krishnamoorthy, N. Raju and V. Ramaswami (Eds.), Advances in Probability Theory and Stochastic Processes, Notable Publications, Neshanic Station, NJ, pp. 21-49.
Chydziński, A. and Chróst, Ł. (2011). Analysis of AQM queues with queue size based packet dropping, International Journal of Applied Mathematics and Computer Science 21(3): 567-577, DOI: 10.2478/v10006-011-0045-7.
Dudin, A., Osipov, E., Dudin, S. and Schelen, O. (2013a). Socio-behavioral scheduling of time-frequency resources for modern mobile operators, Communications in Computer and Information Science 356: 69-82.
Dudin, S., Kim, C. and Dudina, O. (2013b). M MAP/M/N queueing system with impatient heterogeneous customers as a model of a contact center, Computers and Operations Research 40(7): 1790-1803.
Graham, A. (1981). Kronecker Products and Matrix Calculus with Applications, Ellis Horwood, Chichester.
Jouini, O., Aksin, Z. and Dallery, Y. (2011). Call centers with delay information: Models and insights, Manufacturing & Service Operations Management 13(4): 534-548.
Jouini, O., Dallery, Y. and Aksin, Z. (2009). Queuing models for flexible multi-class call centers with real-time anticipated delays, International Journal of Production Economics 120(2): 389-399.
Kesten, H. and Runnenburg, J. (1956). Priority in Waiting Line Problems, Mathematisch Centrum, Amsterdam.
Kim, C., Dudin, A., Klimenok, V. and Khramova, V. (2010a). Erlang loss queueing system with batch arrivals operating in a random environment, Computers and Operations Research 36(3): 674-697.
Kim, C., Klimenok, V., Mushko, V. and Dudin, A. (2010b). The BM AP/PH/N retrial queueing system operating in Markovian random environment, Computers and Operations Research 37(7): 1228-1237.
Kim, C., Dudin, S., Dudin, A. and Dudina, O. (2013a). Queueing system M AP/PH/N/R with session arrivals operating in random environment, Communications in Computer and Information Science 370: 406-415.
Kim, C., Dudin, S., Taramin, O. and Baek, J. (2013b). Queueing system M MAP/PH/N/N+R with impatient heterogeneous customers as a model of call center, Applied Mathematical Modelling 37(3): 958-976.
Kim, C., Klimenok, V., Lee, S. and Dudin, A. (2007). The BM AP/PH/1 retrial queueing system operating in random environment, Journal of Statistical Planning and Inference 137(12): 3904-3916.
Kim, J. and Park, S. (2010). Outsourcing strategy in two-stage call centers, Computers and Operations Research 37(4): 790-805.
Klimenok, V. and Dudin, A. (2006). Multi-dimensional asymptotically quasi-Toeplitz Markov chains and their application in queueing theory, Queueing Systems 54(4): 245-259.
Krieger, U., Klimenok, V., Kazimirsky, A., Breuer, L. and Dudin, A. (2005). A BM AP/PH/1 queue with feedback operating in a random environment, Mathematical and Computer Modelling 41(8-9): 867-882.
Lucantoni, D. (1991). New results on the single server queue with a batch Markovian arrival process, Communication in Statistics-Stochastic Models 7(1): 1-46.
Neuts, M. (1981). Matrix-geometric Solutions in Stochastic Models-An Algorithmic Approach, Johns Hopkins University Press, Baltimore, MD.
Olwal, T., Djouani, K., Kogeda, O. and van Wyk, B. (2012). Joint queue-perturbed and weakly coupled power control for wireless backbone networks, International Journal of Applied Mathematics and Computer Science 22(3): 749-764, DOI: 10.2478/v10006-012-0056-z.
van Danzig, D. (1955). Chaines de markof dans les ensembles abstraits et applications aux processus avec regions absorbantes et au probleme des boucles, Annals de l'Institute H. Pioncare 14(3): 145-199.