This paper presents an application of stochastic Petri nets (SPN) to calculate the availability of safety critical on-demand systems. Traditional methods of estimating system reliability include standards—based or field return-based reliability prediction methods. These methods do not take into account the effect of fault-detection capability and penalize the addition of detection circuitry due...

T his paper studies echelon stock (R, nQ) policies in serial production/inventory systems with stochastic demand. We provide a recursive procedure to compute the steady state echelon inventory levels of the systems, which can be used to evaluate the long-run average holding and backorder costs as well as other performance measures. The procedure is based upon an observation of a relationship be...

The historical data on the consumption of spares are usually available in the form that the renewal function of the item could not easily be obtained by the process described by Cox1. In this paper, b technique is discussed as to how such data be used for the renewal functions through Bayesian approach. A Beta a Priori density for the parameter of Poisson demand is assumed and the Predictive de...

We study a single-item r q inventory system, where r is the reorder point and q is the order quantity. The demand is a compound-Poisson process. We investigate the behavior of the optimal policy parameters and the long-run average cost of the system in response to stochastically shorter or less-variable lead times. We show that although some of the properties of the base-stock system can be ext...

A two-stage inventory system is considered where Poisson demand occurs at Stage 1, and Stage 1 replenishes its inventory from Stage 2, which in turn orders from an outside supplier with unlimited stock. Each shipment, either to Stage 2 or to Stage 1, incurs a fixed setup cost. Under the assumption that the supply leadtime at Stage 2 is zero, we characterize a simple heuristic policy whose long-...

In this paper, we present an analysis of optimization and risk calculation in Communication Networks (CNs). The model is proposed for offline traffic engineering optimization with bandwidth allocation and performance analysis. First, we introduce an optimization model in the CN and derive the optimal bandwidth capacity. Then, we analyze the profit shortfall risk in the CN by using a conditional...

We analyze the demand for hedging and insurance by a firm facing cash-flow risks. We study how the firm’s liquidity management policy interacts with two types of risk: a Brownian risk that can be hedged through a financial derivative, and a Poisson risk that can be insured by an insurance contract. We find that the patterns of insurance and hedging decisions are pole apart: cash-poor firms shou...

A controversial recreation activity is off-highway vehicle use. Off-highway vehicle use is controversial because it is incompatible with most other activities and is extremely hard on natural eco-systems. This study estimates utility theoretic incomplete demand systems for four off-highway vehicle sites. Since two sets of restrictions are equally consistent with utility theory both are imposed ...

We study an M/G/1 queue with second optional service. Poisson arrivals with mean arrival rate λ (> 0), all demand the first ‘essential’ service, whereas only some of them demand the second ‘optional’ service. The service times of the first essential service are assumed to follow a general (arbitrary) distribution with distribution function B1(v) and that of the second optional service with gene...