We review studies based on analytic and simulation methods for hierarchical performance analysis of Queueing Network - QN models, which result in an order of magnitude reduction in performance evaluation cost with respect to simulation. The computational cost at the lower level is reduced when the computer system is modeled as a product-form QN. A Continuous Time Markov Chain - CTMC or discrete-event simulation can then be used at the higher level. We first consider a multiprogrammed transaction - txn processing system with Poisson arrivals and predeclared locks requests. Txn throughputs obtained by the analysis of multiprogrammed computer systems serve as the transition rates in a higher level CTMC to determine txn response times. We next analyze a task system where task precedence relationships are specified by a directed acyclic graph to determine its makespan. Task service demands are specified on the devices of a computer system. The composition of tasks in execution determines txn throughputs, which serve as transition rates among the states of the higher level CTMC model. As a third example we consider the hierarchical simulation of a timesharing system with two user classes. Txn throughputs in processing various combinations of requests are obtained by analyzing a closed product-form QN model. A discrete event simulator is provided. More detailed QN modeling parameters, such as the distribution of the number of cycles in central server model - CSM affects the performance of a fork/join queueing system. This detail can be taken into account in Schwetman's hybrid simulation method, which counts remaining cycles in CSM. We propose an extension to hybrid simulation to adjust job service demands according to elapsed time, rather than counting cycles. An example where Equilibrium Point Analysis to reduce computaional cost is privided.

翻译：本文综述了基于解析与仿真方法对排队网络（QN）模型进行分层性能分析的研究。与直接仿真相比，该方法可将性能评估成本降低一个数量级。当计算机系统建模为乘积形式QN时，底层计算成本得以降低，而高层可采用连续时间马尔可夫链（CTMC）或离散事件仿真方法。首先考虑具有泊松到达与预声明锁请求的多道程序事务（Txn）处理系统：通过多道程序计算机系统分析获得的事务吞吐量，作为高层CTMC中的状态转移率，用于确定事务响应时间。其次分析任务系统：任务间的优先关系由有向无环图指定，以确定其完工时间。任务服务需求在计算机系统设备上定义，执行中任务的组合决定事务吞吐量，该吞吐量作为高层CTMC模型状态间的转移率。第三个案例研究具有两类用户的分时系统分层仿真：通过分析封闭乘积形式QN模型获得不同请求组合下的事务吞吐量，并提供离散事件仿真器。更详细的QN建模参数（如中央服务器模型（CSM）中循环次数分布）会影响分叉/合并排队系统的性能。Schwetman的混合仿真方法通过计数CSM中剩余循环次数可考虑该细节。本文提出混合仿真的扩展方法，根据经过时间调整作业服务需求而非计数循环次数，并给出利用平衡点分析降低计算成本的示例。