Number Of Redundant Units Research Articles

Availability and Productivity of Simple Production Chains

Stochastic Markov process is formulated for a system of independent production machines with few redundant units in cold, warm or hot standby regime. The disposable repair capacity is restricted. Resulting system of Kolmogorov-Chapman differential equations is solved numerically for different configurations of the production system. Time evolution is relatively insensitive on the renewal capacity and the number of redundant units. The steady state is completely determined by the ratio of failure and the repair rate. Effectiveness of the system as measured by the volume of production is markedly influenced also by such factors as are the renewal capacity and the number of redundant units.

Design and Inspection Policy for Redundant Systems Using Information of Warranty

This paper considers the problem of determining the optimal number of redundant units in redundant systems with random unit failures and warranty. Parallel and k out of n systems are considered. The optimal number of redundant units which minimize the expected cost rate is found and the number is shown to be finite and unique. For given inspection interval before expiration of warranty, the optimal number of redundant units is also obtained. The effects of inspection and the warranty to the optimal number of redundant units are studied.

Redundancy optimization of k-out-of-n systems with common-cause failures

The problem of determining the optimal number of redundant units in k-out-of-n systems with common-cause failures (CCFs) is discussed. The mean cost rate is obtained, its behavior is examined considering both CCFs and random failures of the units, and the number of redundant units minimizing the mean cost rate is shown to be finite and unique. For the problem of determining the optimal number of redundant units and inspection period, the mean cost rate is obtained and a solution procedure is presented. Numerical studies are given which indicate that CCFs tend to reduce the optimal number of redundant units. >

Optimal numbers of redundant units for parallel systems with common mode failures

This paper considers the problem of determining optimal numbers of redundant units in parallel systems with common mode failures. Cost models are obtained considering both the common mode failures and the component's random failures. The number of redundant units minimizing the expected cost rates is shown to be finite and unique.

Technological reliability and its safeguards in mining operations

The method described in this paper makes it possible to use statistical data on the operation of machines and mechanisms in a mining system to evaluate the optimum maintenance periods for each type of equipment. This period should be incorporated into the mining operation procedure. In addition, the data on the equipment reliability can be used to calculate which types of machines are needed and the number of redundant units, ensuring a given reliability of the system. These recommendations, if incorporated in a planned procedure, will yield a desired speed of excavation advance and efficient utilization of available equipment.

A Rapid Algorithm For Reliability Optimisation Of Parallel Redundant Systems

A rapid method is proposed for optimization of reliability of multiconstraint parallel redundant systems. The constraints need not be linear. This method provides good starting values, which are close to the boundary of the feasible region, for the number of redundant units in each subsystem. No proof has been presented to establish the optimality obtained by this method. Yet for examples tried out this method provides optimal or near optimal solutions.

Optimal Design of a Series-Parallel System with Time-Dependent Reliability

The paper formulates an optimal reliability design problem for a series system made of parallel redundant subsystems. The variables for optimization are the number of redundant units in each subsystem and the reliability of each unit. There is a cost-constraint. The time for which the system reliability exceeds a specified value is to be maximized. Similarly the cost could be minimized for a constraint on the mission time and reliability. A solution method for the formulated problems is presented along with an example.