Manufacturing flow line systems: a review of models and analytical results

The most important models and results of the manufacturing flow line literature are described. These include the major classes of models (asynchronous, synchronous, and continuous); the major features (blocking, processing times, failures and repairs); the major properties (conservation of flow, flow rate-idle time, reversibility, and others); and the relationships among different models. Exact and approximate methods for obtaining quantitative measures of performance are also reviewed. The exact methods are appropriate for small systems. The approximate methods, which are the only means available for large systems, are generally based on decomposition, and make use of the exact methods for small systems. Extensions are briefly discussed. Directions for future research are suggested.National Science Foundation (U.S.) (Grant DDM-8914277

Stochastic Modeling of Processor Scheduling with Application to Database Management Systems

Abstract: This paper is concerned with the stochastic modeling of processor scheduling and of queuing due to contention for re-sources in data base management systems. The processing services rendered in searching the data base and retrieving and processing information are modeled explicitly, as is the algorithm used to schedule these services on the processor. The scheduling of the proces-sor is based on a total priority ordering of a set of queues for processing service. A queuing model incorporating the processor schedul-ing algorithm for IMS (Information Management System) is formulated in order to illustrate the modeling ideas. The model is analyzed under rather general distributional assumptions, based on the observation that certain stochastic processes in the model are cumulative processes defined over the same embedded semiMarkov process. The model is not used in a performance study of IMS, nor is it pro-posed that the model developed here is one upon which a performance study of IMS should be undertaken. The model should be viewed as illustrative of stochastic models which can be constructed to incorporate algorithms for processor scheduling

The Steady-State Queueing Time Distribution for the M/G/1 Finite Capacity Queue

We derive an expression for the Laplace-Stieltjes transform of the steady-state distribution of the queueing time for the M/G/1 finite capacity queue. The derivation proceeds in terms of a related 2-stage closed cyclic queueing network. The resulting expression is a rational function of the steady-state probabilities of the imbedded Markov chain at departure epochs and of the Laplace-Stieltjes transform of the service time distribution. The expression can be differentiated readily in order to obtain moments of the steady-state queueing time and some numerical results for the mean and coefficient of variation are presented.

I

Abstract: A recently developed method for estimating confidence intervals when simulating stochastic systems having a regenerative structure is reviewed. The paper is basically tutorial, but also considers the pragmatic issue of the simulation duration required to obtain valid estimates. The method is illustrated in terms of simulating the M/G / 1 queue. Analytic results for the M/G / 1 queue are used t

Analytical performance modeling for computer systems

10.2200/S00282ED1V01Y201005CSL002Synthesis Lectures on Computer Science21-10