Manufacturers are today striving to offer value-added Product Service System (PSS) with the purpose of achieving higher competiveness and more environmental benefits. Requirement elicitation and evaluation with sustainability concerns play a key role in a successful development of sustainable PSS. However, the previous literature rarely address the PSS requirement from the view of sustainability, while mainly focusing on the customer satisfaction. To accurately identify the requirement with respect to sustainable value from a long term perspective, it is necessary to develop effective methods for requirement elicitation for sustainable PSS. In addition, the prioritization of sustainable value requirement provides critical guidance for the later PSS design. The prioritization involves much judgement ambiguousness and diversity which may lead to inaccurate requirement analysis result. However, there are few researches on combinatory manipulation of the vagueness and diversity. Therefore, to solve these problems, an innovative methodology incorporating requirement elicitation and evaluation is developed for sustainable PSS. This study introduces the concept of value uncaptured into the identification of product value state, and offers the Product Value State Model (PVSM) method to elicit value requirements which help PSS deliver more sustainability. Moreover, a hybrid model for evaluating the sustainable value requirement is proposed by combining the fuzzy set, rough set, Decision Making Trial and Evaluation Laboratory (DEMATEL) and Analytical Network Process (ANP) methods. An application in an excavator PSS and the comparisons with some different methods demonstrate the feasibility and potential of the methodology. Theoretically, the proposed evaluation model provides more accurate and realistic analysis results of PSS requirements compared to traditional methods, since it supports to simultaneously manipulate judgement vagueness, group decision diversity, and complex interrelationship. In practical PSS design, the method helps PSS designers successfully recognize the most key value requirements with both respect of sustainability and customer satisfaction.

如今，制造商正在努力提供增值产品服务系统（PSS），以实现更高的竞争力和更多的环境效益。涉及可持续性问题的需求启发和评估在可持续性PSS的成功开发中起着关键作用。但是，以往的文献很少从可持续性的角度来论述PSS要求，而主要集中在客户满意度上。为了从长期角度准确地确定关于可持续价值的需求，有必要开发出有效的方法来激发可持续PSS的需求。此外，可持续价值要求的优先次序为以后的PSS设计提供了重要的指导。优先级划分涉及很多判断模棱两可和多样性，可能导致需求分析结果不准确。但是，关于模糊性和多样性的组合操纵的研究很少。因此，为了解决这些问题，针对可持续的PSS开发了一种将需求启发和评估相结合的创新方法。这项研究将未捕获的价值概念引入到产品价值状态的识别中，并提供了产品价值状态模型（PVSM）方法来得出价值要求，这有助于PSS提供更多的可持续性。此外，通过结合模糊集，粗糙集，决策试验与评估实验室（DEMATEL）和分析网络过程（ANP）方法，提出了一种用于评估可持续价值要求的混合模型。在挖掘机PSS中的应用以及与一些不同方法的比较证明了该方法的可行性和潜力。从理论上讲，与传统方法相比，所提出的评估模型提供了对PSS要求的更准确和现实的分析结果，因为它支持同时处理判断模糊性，群体决策多样性和复杂的相互关系。在实际的PSS设计中，该方法可帮助PSS设计人员成功地在可持续性和客户满意度方面识别最关键的价值要求。与传统方法相比，该提议的评估模型提供了对PSS要求的更准确和现实的分析结果，因为它支持同时处理判断模糊性，群体决策多样性和复杂的相互关系。在实际的PSS设计中，该方法可帮助PSS设计人员成功地在可持续性和客户满意度方面识别最关键的价值要求。与传统方法相比，该提议的评估模型提供了对PSS要求的更准确和现实的分析结果，因为它支持同时处理判断模糊性，群体决策多样性和复杂的相互关系。在实际的PSS设计中，该方法可帮助PSS设计人员成功地在可持续性和客户满意度方面识别最关键的价值要求。