Innovation portfolio management: a systematic review and research agenda in regards to digital service innovations

Portfolio Management (PM) for innovation is as relevant as ever before as many incumbent firms undergo massive transformation in response to digitalization and face the challenge to allocate resources for traditional product innovation and service innovation projects more efficiently and effectively. Digital service innovations, regarded as new business fields for many industrial firms are in the forefront of much discussion in practice and academia; nonetheless, it is unclear to what extent existing innovation PM has acknowledged how to manage a portfolio of service and digital service innovations. To address this gap, this work sets out to (1) review and synthesize decades of contributions in the field of innovation PM in a structured way, (2) examine to what extent research has considered and elaborated on innovation PM for services and digital services, and finally (3) provide a research agenda to foster future contributions in this field. We classified relevant findings in innovation PM into four categories (antecedents, consequences, models/frameworks, challenges) and found that literature has acknowledged services more than anticipated, but that still much of today's innovation PM research is focused on physical products. In more recent years, the attention towards services has resulted in a few publications delving into the differences between service and product innovation PM; however, digital service innovations have been overlooked by the research so far. Lastly, we point out how innovation PM for services and digital services may diverge from traditional products and outline a research agenda.