In response to the escalating need for sustainable production and consumption, manufacturers increasingly adopt Life-Cycle Design (LCD) to address environmental and social challenges. However, the complex nature of cross-organizational collaborations in LCD often leads to conflicts among stakeholders, hindering effective implementation. This study aims to address this gap by proposing a comprehensive method framework for characterizing, evaluating, and improving manufacturers' LCD Conflict Managing Capabilities (LCD-CMC). The study begins by explicating conflicts in LCD and introduces the People-Process-Technology Framework. This framework serves to comprehensively characterize LCD-CMC and to break down the abstract LCD-CMC concept into specific elements in three dimensions. Subsequently, a Maturity Model is developed for quantitatively evaluating LCD-CMC, utilizing a hybrid method integrating Decision-making Trial and Evaluation Laboratory (DEMATEL) and Analytical Network Process (ANP). DEMATEL enables the identification and quantification of interrelations among multiple criteria of the LCD-CMC evaluation system, while ANP facilitates the weighting of each criterion based on its significance. Together, these methodologies enable a comprehensive assessment of the maturity level of LCD-CMC. Building upon this foundation, a systematic approach for generating improvement strategies for LCD-CMC is proposed, leveraging the Total Adversarial Interpretive Structure Model (TAISM) to analyze the inter-relations among contributing capability elements. TAISM offers a practical approach to generating robust improvement strategies, ensuring effective and efficient improvements in LCD-CMC over time. Through a case study involving a prominent Chinese machine tool manufacturer, the feasibility and efficacy of our framework are demonstrated, providing valuable insights into potential improvements. Overall, this paper offers valuable insights into managing conflicts in LCD, providing a structured methodology for evaluating and improving LCD-CMC. By leveraging advanced models and methods, it contributes to addressing LCD conflicts and enhancing collaboration in LCD implementation. Furthermore, it contributes to enriching the knowledge of Life-Cycle Design in the context of conflict management, ultimately advancing sustainable production and consumption practices.