<p>This article investigates the steady-state behavior of a single-server retrial queue in which arriving units select one of two heterogeneous service types, each followed by an optional immediate re-service of the same type. Units encountering a busy server join a retrial orbit and attempt to access the server after a random delay governed by classical retrial policy. Using the supplementary variable technique, we have derived the Laplace–Stieltjes transforms of the probability generating functions for the number of units in the orbit and in the system. The stochastic decomposition property is established, and pivotal system characteristics, such as the mean and variance of the orbit size, system size, and waiting times both in orbit and in the system are obtained. To validate the analytical results and study the effect of key system parameters, numerical experiments are conducted across three service time distributions namely, exponential, 2-stage Erlang and Hyper-exponential distribution. A cost optimization is carried out employing the parabolic method to identify the optimal arrival rate that minimizes the total expected operating cost per unit time.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Performance analysis of a single server retrial queue with two heterogeneous service under re-service policy

  • Hirak Jyoti Sarma,
  • Gautam Choudhury,
  • Anjana Begum

摘要

This article investigates the steady-state behavior of a single-server retrial queue in which arriving units select one of two heterogeneous service types, each followed by an optional immediate re-service of the same type. Units encountering a busy server join a retrial orbit and attempt to access the server after a random delay governed by classical retrial policy. Using the supplementary variable technique, we have derived the Laplace–Stieltjes transforms of the probability generating functions for the number of units in the orbit and in the system. The stochastic decomposition property is established, and pivotal system characteristics, such as the mean and variance of the orbit size, system size, and waiting times both in orbit and in the system are obtained. To validate the analytical results and study the effect of key system parameters, numerical experiments are conducted across three service time distributions namely, exponential, 2-stage Erlang and Hyper-exponential distribution. A cost optimization is carried out employing the parabolic method to identify the optimal arrival rate that minimizes the total expected operating cost per unit time.