## Abstract

For theM/M/1+Mmodel at the law-of-large-numbers scale, the long-run reneging count per unit time does not depend on the individual (i.e., per customer) reneging rate. This paradoxical statement has a simple proof. Less obvious is a large deviations analogue of this fact, stated as follows: The decay rate of the probability that the long-run reneging count per unit time is atypically large or atypically small does not depend on the individual reneging rate. In this paper, the sample path large deviations principle for the model is proved and the rate function is computed. Next, large time asymptotics for the reneging rate are studied for the case when the arrival rate exceeds the service rate. The key ingredient is a calculus of variations analysis of the variational problem associated with atypical reneging. A characterization of the aforementioned decay rate, given explicitly in terms of the arrival and service rate parameters of themodel, is provided yielding a precise mathematical description of this paradoxical behavior.

Original language | English |
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Pages (from-to) | 232-258 |

Number of pages | 27 |

Journal | Mathematics of Operations Research |

Volume | 47 |

Issue number | 1 |

Early online date | 21 Jul 2021 |

DOIs | |

State | Published - Feb 2022 |

## Keywords

- Euler-Lagrange equations
- Laplace principle
- Reneging
- Sample path large deviations
- Single-server queue
- The reneging paradox

## All Science Journal Classification (ASJC) codes

- Computer Science Applications
- General Mathematics
- Management Science and Operations Research