Measuring ecosystem openness in open innovation: The shared mobility ecosystem openness indicator

Shared mobility platform systems, from bikes and scooters to car-based services, promise cleaner, smarter transportation. Yet in practice, many fail to scale or sustain due to fragmented data, misaligned incentives, and a lack of ecosystem coordination. While open innovation is often promoted as a remedy, openness in these systems remains symbolic, informal, or inconsistently applied. This article builds on the theoretical foundations of strategic management, open innovation, ecosystem thinking, and platformization to reconceptualize shared mobility as a complex, governed system rather than a set of disconnected services. The work introduces the Shared Mobility Ecosystem Openness Indicator (SMEOI): a strategic, multi-dimensional index designed to help platform leaders, operators, and public agencies measure, manage, and institutionalize openness across six critical domains - data availability, technological modularity, ecosystem collaboration, business model design, user participation, and regulatory transparency. By reframing openness as a governance variable, the SMEOI bridges open innovation theory with the operational realities of mobility management. Openness is presented not as a voluntary gesture, but as an architectural design choice that drives integration, fosters trust, and aligns innovation with policy. To support implementation, we propose a gamified scoring model, classifying platforms into intuitive openness tiers, and a six-step roadmap for transforming openness from a vision into a repeatable capability. For executives, the SMEOI offers a strategic lens to differentiate and govern platforms. For policymakers, it provides a tool to benchmark systems, enforce standards, and coordinate multi-actor innovation. Ultimately, this work calls for a shift: from openness as intention to openness as infrastructure.