Predetermined standby mode transfers in 1-out-of-N systems with resource-constrained elements

•1-out-of-N standby system is considered.•Elements can be in two standby modes with different activation readiness.•The standby mode transfers occur in predetermined time.•Each element has limited resource and is inactivated upon resource depletion.•An algorithm for evaluating mission downtime is suggested.•Optimal mode transfer schedule is found.