摘要：This article proposes to bring the sustainable product-service innovation (PSI) field into a next phase—after two phases of exploring why and how firms achieve sustainable PSI growth, we suggest to further focus on finding <i>when</i> they actually do so. Based on prior studies, we pinpoint and describe two main shortcomings in the current body of PSI literature: (1) an overemphasis on the firm level, and (2) an overuse of descriptive case studies. These shortcomings are used as stepping-stones for formulating a research approach that integrates <i>Multiple Levels</i> (namely, the firm, its environment, and its people), mixes different <i>Methods</i> (both qualitative and quantitative) and that turns researchers to <i>Action</i> (through advice and training). This MLMA approach offers ample new research opportunities and turns the servitization research community into a <i>servitized</i> community by leveraging academic insights to better support firms in improving their economic and environmental performance.
