This　paper　proposes　a　base　warranty　and　replacement　warranty　strategy　for　repairable　products.　It　should　be　emphasized　that　the　product　failure　rate　is　low　in　the　early　stage　of　the　base　warranty.　Therefore,　in　order　to　reduce　the　manufacturer’s　maintenance　cost,　the　manufacturer　does　not　carry　out　preventive　maintenance　in　the　early　stage　of　the　base　warranty,　and　carries　out　regular　preventive　maintenance　in　the　later　stage　of　the　base　warranty.　At　the　same　time,　if　the　number　of　product　failures　in　the　base　warranty　exceeds　the　specified　limit,　the　manufacturer　must　replace　products　for　customers　free　of　charge　according　to　the　warranty　contract.　After　the　product　is　replaced,　if　the　number　of　product　failures　does　not　exceed　the　limit,　the　manufacturer　will　continue　to　provide　customers　with　the　remaining　base　warranty　period　of　the　original　product,　and　the　warranty　period　will　continue　to　be　extended　for　a　period　of　time.　By　minimizing　the　expected　cost　rate,　it　is　shown　that　the　optimal　maintenance　policy　for　warranty　products　is　unique.　Finally,　we　give　a　numerical　example　and　study　the　effects　of　periodic　preventive　maintenance　and　other　relevant　parameters　on　the　optimal　solution.　©　IMechE　2024.