Motivated by service systems, such as telephone call centers and emergency departments, we consider admission control for a two-class multi-server loss system with periodically varying parameters and customers who may abandon from service. Assuming mild conditions for the parameters, a dynamic programming formulation is developed. We show that under the infinite horizon discounted problem, there exists an optimal threshold policy and provide conditions for a customer class to be preferred for each fixed time, extending stationary results to the non-stationary setting. We approximate the non-stationary problem by discretizing the time horizon into equally spaced intervals and examine how policies for this approximation change as a function of time and parameters numerically. We compare the performance of these approximations with several admission policies used in practice in a discrete-event simulation study. We show that simpler admission policies that ignore non-stationarity or abandonments lead to significant losses in rewards.

中文翻译：

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具有周期性变化的参数和放弃的二级损失系统中的准入控制

受电话呼叫中心和急诊部门等服务系统的驱动，我们考虑对具有周期性变化的参数和可能放弃服务的客户的二类多服务器丢失系统进行准入控制。假设参数条件温和，则开发了动态规划公式。我们表明，在无限期贴现问题下，存在一个最优阈值策略，并为每个固定时间首选的客户类别提供条件，将平稳结果扩展到非平稳设置。我们通过将时间范围离散为等距间隔来近似非平稳问题，并检查这种近似的策略如何作为时间和参数的函数在数值上变化。我们将这些近似值的性能与离散事件模拟研究中实践中使用的几种准入策略进行了比较。我们表明，忽略非平稳性或放弃的更简单的录取政策会导致奖励的重大损失。