Developing medical device innovations is a lengthy and costly endeavor, so engaging the right participants early in the process is crucial. While much of the existing literature focuses on procedural aspects of innovation, the human factors that influence success are often overlooked. The Lead User Method is designed to identify key contributors based on their ability to stay ahead of market trends and realize significant benefits. However, it has been criticized for inadequacies in its identification process. To address this gap, our study distinguishes seven key personal characteristics of medical lead users that are essential for successful co-created new product development. Through case studies and semi-structured interviews, we demonstrate that engaging lead users throughout the new product development process—regardless of product complexity—enhances product-market fit and profitability. Their involvement becomes increasingly critical as the process advances, particularly during the market diffusion phase. Our research refines the Lead User Method's identification process and provides actionable insights for decision-makers, reducing uncertainty in medical device innovation while lowering development costs and time and increasing product-market fit and profitability.

Despite the promising ideas of lead users, the success rate of the open innovation process remains low if no proper personal characteristics are attached to the external contributor. The knowledge about the essential characteristic elements of lead users is crucial to select the right lead users in the early stage of the NPD. By filling the research gap, we performed a systematic literature review about the required personal characteristics of lead users. The resulting 45 studies demonstrated that diverse characteristics are required in different stages of an NDP which vary in the consumer and industrial context. According to our research results, we made a contribution to the theory by extending the lead user method in the form of a partial theory. We also found that in the case of incremental innovations, companies apply their technical knowledge and do not require additional expertise from users, while in the case of radical innovations, firms only involve external users with high technological competencies in the development stage of the NDP. We identified similarities and differences of the required lead users’ personal characteristics in the consumer and industrial contexts. Thus, our study provides a better awareness for business leaders on the selection of lead users for their NPD process, reducing the time-to-market ratio of the product and increasing profit.