Random replacement strategies modeling through back and front warranties with preventive maintenance

In the context of advanced digital technology enabling real-time monitoring of data elements throughout the product lifecycle, numerous researchers have proposed multi-dimensional random warranties integrating monitored missions. However, some key aspects have been commonly overlooked. For example, when the principle of ’whichever occurs first’ or ’whichever occurs last’ is adopted to handle warranty-expiry limits, the heterogeneous durations of warranty time will either reduce the warranty time for the consumers or increase the warranty cost for the manufacturers. To address these issues, this paper proposes two random warranties, each of which is combined with mission elements. The proposed warranties include a random renewable repair back warranty and a random renewable repair front warranty with preventive maintenance (PM) designed to control warranty time and cost by dynamic means. Additionally, extending the design concepts derived from these warranties to the post-warranty scopes, this paper defines and models a random renewable-periodic back replacement strategy and a random renewable-periodic front replacement strategy with PM, which can flexibly sustain post-warranty reliabilities. Finally, a numerical analysis is carried out to explore the insights and effectiveness of the proposed method, demonstrating that the proposed warranties are superior and the proposed replacement strategies are effective.