Dynamic availability assessment and optimal component design of multi-state weighted k-out-of-n systems

•A dynamic availability model is developed for multi-state weighted k-out-of-n systems.•Optimization problems for the design of multi-state weighted k-out-of-n systems are formulized based on the dynamic availability model.•Dynamic optimal design is not necessarily only one best solution during the time.

Availability/reliability is a main feature of design and operation of all engineering systems. Recently, availability evaluation of multi-state systems with different structures is at the center of attention due to the wide applications in engineering. In this paper, a dynamic model is developed for the availability assessment of multi-state weighted k-out-of-n systems. Then, in a design optimization problem, the availability and capacity for the components of such systems are optimized by genetic algorithm. In the dynamic model, the probabilities and capacities of components in different states are allowed to be changed over time. For availability assessment, universal generating function and Markov process are adopted. Application of the proposed model is illustrated using a real-world marine transportation system in order to evaluate and compare the presented optimization problems in assessing system availability.