Due to the non-substitutability of the product, the monopoly manufacturer designs warranty to reduce maximally warranty cost. Although the monopoly manufacturer maintains responsibly product reliability in warranty, the consumer still confronts a problem about how to sustain product reliability after the designed warranty expires. Goal of this paper is, from the consumer’s perspective, to propose a reliability maintenance policy after expiry of the monopoly manufacturer’s warranty. First, a renewable repair-limit pro-rata replacement warranty (RRLPRRW) policy is considered from viewpoint of the monopoly manufacturer and used as a quality guarantee of the product with the deterioration affected by internal aging and external shock. Second, depreciation cost is earlier considered in the process of modeling life cycle cost, which differs from the traditional works on the consumer’s post-warranty reliability maintenance problem. Third, the consumer’s discounted cost rate model considering depreciation cost is derived to achieve optimal maintenance policy. Finally, a numerical example is provided to illustrate our approach. It was found that the proposed maintenance policy is more effective and the depreciation cost considered in life cycle cost has significant effect on extension of the post-warranty period.

由于产品不可替代，因此垄断制造商会设计保修，以最大程度地降低保修成本。尽管垄断制造商负责任地在保修中保持产品可靠性，但是消费者仍然面临在设计的保修期满后如何保持产品可靠性的问题。从消费者的角度来看，本文的目的是在垄断制造商的保修到期后提出可靠性维护策略。首先，从垄断制造商的角度考虑了可再生维修极限按比例更换保修（RRLPRRW）政策，该政策被用作对产品质量的保证，该产品受内部老化和外部冲击的影响而变质。其次，在对生命周期成本进行建模的过程中，折旧成本已被提前考虑，这与传统的关于消费者保修后可靠性维护问题的作品不同。第三，推导了考虑折旧成本的消费者折扣成本率模型，以实现最佳维护策略。最后，提供了一个数值示例来说明我们的方法。结果发现，拟议的维护策略更加有效，生命周期成本中考虑的折旧成本对保修后期限的延长具有重大影响。