بهينه‌سازي چندهدفه‌ي مسيله‌ي مركز تماس چندگانه با استفاده از متدولوژي سطح پاسخ

A Multi-Objective Optimization Approach to Solving Multi-Call Center Problems Based on Response Surface Methodology

سيستم هاي مركز تماس يكي از پركاربردترين سيستم هاي مورد استفاده در مراكز و سازمان ها براي پاسخ‌گويي به سوالات مشتريان است. طراحي و پيكربندي بهينه‌ي سيستم يكي از مسايل و حوزه هاي اصلي به‌خصوص براي مراكز تماس چندگانه است. در اين ارتباط، افزايش كارايي امكانات سيستم، به‌ويژه نيروي انساني از يك سو و افزايش رضايت مشتريان از سوي ديگر، مهم‌ترين اهداف سيستم هاي مركز تماس است. طي سال‌هاي اخير رويكردهاي متنوعي براي حل اين مسيله ارايه ‌شده، اما بيشتر اين رويكردها تنها به تحليل عملكرد مركز مي پردازند. رويكردهاي بهينه سازي ارايه شده نيز صرفاً از ديدگاه مشتري يا كارفرما طراحي شده اند. در اين مطالعه يك رويكرد بهينه‌سازي براساس متدولوژي سطح پاسخ و طراحي آزمايشات پيشنهاد شده، كه نه‌تنها به‌طور همزمان رضايت مشتريان و بهره وري امكانات مركز تماس را بيشينه مي‌كند، بلكه همبستگي بالقوه بين اهداف را نيز ضمن تلاش براي كمينه‌سازي اثر متغيرهاي غير قابل كنترل (عوامل اختلال) روي اهداف لحاظ مي‌كند.

A call center is a centralized office used for the purpose of receiving and transmitting a large volume of requests by telephone. A call centre often operates through an extensive open workspace for call centre agents, with work stations that include a computer for each agent, a telephone set/headset connected to a telecom switch, and one or more supervisor stations. Call centers can operate independently or be networked with additional centers, called a multi call center. System configuration optimization is one of the main problems in multi call centers. Improvement of system utilization and customer satisfaction are the most important objectives in a call center system. In recent years, different approaches have been developed for solving this problem. Most of these approaches only stress the analysis of system performance. Furthermore, these approaches usually focus on either customer or employer viewpoints. In this paper, a multi-objective optimization approach, based on response surface methodology and the design of experiments, is proposed. The proposed approach maximizes customer satisfaction and system utilization simultaneously. Response surface methodology (RSM) is a collection of mathematical and statistical techniques that are useful for modeling and analysis in applications where responses of interest are influenced by several variables, and the objective is to optimize these responses simultaneously. In the proposed approach, decision variables are the number of operators in any center, number of links between centers and length of waiting queue. Simultaneous objectives include maximization of operator utilization and link utilization; minimization of the percentage of balking calls, and customers waiting time in the system. The proposed approach consists of three phases; design of experiments, simulation and optimization. First, a factorial design is developed to evaluate system performances. Then, an aggregated method is used to convert various objectives into a single objective function. In this study, the aggregation measure is the probability of all four objective functions simultaneously meeting their desirable regions ( ). In order to estimate this measure, we simulate the system. In the next step, the response surface of the aggregated measure, with respect to design variables, is obtained. Finally, by maximization of , optimum values of factors are obtained. The validity and performance of the proposed method were investigated on the data of a multi call center system consisting of three call centers. The results of the proposed method were compared with the solutions of common methods in the literature. The result of the proposed method outperformed the results obtained by other approaches.