We study the sojourn time in a queueing system with a single exponential server, serving a Poisson stream of customers in order of arrival. Service is provided at a low or high rate, which can be adapted at exponential inspection times. When the number of customers in the system is above a given threshold, the service rate is upgraded to the high rate, otherwise, it is downgraded to the low rat...

This paper exhibits a stochastic model which describes the evolution of a material submitted to inspections. When an inspection takes place, a decision depending on the observed state of the material is taken. If the material is in "not too bad" state, no service is rendered, only the date of the next inspection is chosen. If the material is in a "bad" working state, a service takes place. Roug...

Corrosion is a random phenomenon which reduces the strength of pipeline systems over time. Continuous operation of such systems involves significant expenditures in inspection and maintenance. The costeffective safety management of pipeline systems involves finding the appropriate amount of resources to allocate to initial design and to inspection and maintenance activities, in order to keep ex...

This study proposes a general methodology for determining the optimal lifetime planning of bridge inspection and repair programs based on minimizing the ex­ pected cost while maintaining an acceptable level of reliability. For individual bridges, this methodology determines the optimum inspection technique. and the numbers and timing of inspections and repairs. The methodology is demonstrat­ ed...

Non-destructive testing (NDI) techniques are routinely used in bridge inspection. However, detection accuracy, accessibility, cost and consequences of false indication are all factors to consider when selecting the NDI techniques to be used. A probabilistic method is proposed to help select the most suitable NDI technique and an associated optimal schedule for fracture-critical member/detail in...

This paper presents a degradation-based model to jointly determine the optimal burn-in, inspection, and maintenance decisions, based on degradation analysis and an integrated quality and reliability cost model. Degradation modeling plays an important role in reliability prediction and analysis for many highly reliable components and equipment, when the failures can rarely be observed. Unlike tr...

A batch production process that is initially in the in-control state can fail with constant failure rate to the out-of-control state. The probability that a unit is conforming if produced while the process is in control is constant and higher than the respective constant conformance probability while the process is out of control. When production ends, the units are inspected in the order they ...

This paper presents a degradation-based model to jointly determine the optimal burn-in, inspection, and maintenance decisions, based on degradation analysis and an integrated quality and reliability cost model. Degradation modeling plays an important role in reliability prediction and analysis for many highly reliable components and equipment, when the failures can rarely be observed. Unlike tr...

In this paper I model the optimal monitoring and enforcement strategy when inspection capacity is fixed by budget or manpower constraints. I adopt a leverage enforcement structure that classifies firms into two groups with different enforcement intensities. Optimal monitoring and enforcement requires effective allocation of the fixed number of inspections to the two groups. In each period, a fi...

In order to reduce or eliminate the consequences of the electronic equipment malfunction, some important electronic equipment were installed protection devices. Failures of protection devices are of hidden feature, and can only be found by inspections. Protection device failing to system malfunctioning has a delay characteristic. According to this delay characteristic, an inspection policy was ...