Purpose Obsolescence, as premature end of use, increases the overall number of products produced and consumed, and thereby can increase the environmental impact. Measures to decrease the effects of obsolescence by altering the product or service design have the potential to increase use time (defined as the realized active service life) of devices, but can themselves have (environmental) drawbacks, for example, because the amount of material required for production increases. As such, paying special attention to methodological choices when assessing such measures and strategies using life cycle assessment (LCA) needs is crucial. Methods Open questions and key aspects of obsolescence, including the analysis of its effects and preventative measures, are discussed against the backdrop of the principles and framework for LCA given in ISO 14040/44, which includes guidance on how to define a useful functional unit and reference flow in the context of real-life use time. Results and discussion The open and foundational requirements of ISO 14040/14044 already form an excellent basis for analysis of the phenomenon obsolescence and its environmental impact in product comparisons. However, any analysis presumes clear definition of the goal and scope phase with special attention paid to aspects relevant to obsolescence: the target product and user group needs to be placed into context with the analysed “anti-obsolescence” measures. The reference flow needs to reflect a realized use time (and not solely a technical lifetime when not relevant for the product under study). System boundaries and types of data need to be chosen also in context of the anti-obsolescence measure to include, for example, the production of spare parts to reflect repairable design and/or manufacturer-specific yields to reflect high-quality manufacturing. Conclusions Understanding the relevant obsolescence conditions for the product system under study and how these may differ across the market segment or user types is crucial for a fair and useful comparison and the evaluation of anti-obsolescence measures.

中文翻译：

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LCA 过时——方法论挑战和解决方法

目的 过时作为过早结束使用会增加生产和消费的产品总数，从而增加对环境的影响。通过改变产品或服务设计来减少过时影响的措施有可能增加设备的使用时间（定义为实现的有效使用寿命），但本身可能具有（环境）缺陷，例如，因为材料的数量增产所需。因此，在使用生命周期评估 (LCA) 需求评估此类措施和策略时，特别注意方法选择至关重要。方法 在 ISO 14040/44 中给出的 LCA 原则和框架的背景下，讨论了过时的开放性问题和关键方面，包括对其影响和预防措施的分析，其中包括有关如何在现实生活使用时间的背景下定义有用功能单元和参考流程的指南。结果与讨论 ISO 14040/14044 的开放性和基础性要求已经为分析产品比较中的陈旧现象及其环境影响奠定了良好的基础。然而，任何分析都假定明确定义目标和范围阶段，并特别关注与过时相关的方面：需要将目标产品和用户群置于分析的“反过时”措施的上下文中。参考流程需要反映实现的使用时间（当与所研究的产品不相关时，不仅仅是技术寿命）。还需要在反过时措施的背景下选择系统边界和数据类型，例如，生产备件以反映可修复的设计和/或制造商特定的产量以反映高质量的制造。结论 了解所研究产品系统的相关过时条件以及这些条件在细分市场或用户类型之间可能有何不同，对于公平和有用的比较和反过时措施的评估至关重要。