With the expansion of infrastructure projects in the Netherlands in terms of size and complexity, government bodies are increasingly inclined towards adopting a programmatic approach for managing multiple projects. This approach incorporates innovations to enhance efficiency and effectiveness in achieving program objectives. However, the development and implementation of innovations within these infrastructure programmes encounter various challenges, leading to not optimum utilization of innovations. One significant challenge stem from the limited practical experience in utilizing the programmatic approach, resulting in a limited understanding of both the programme's context and innovation process in multi-projects. Consequently, innovations tend to be developed and implemented using a project-based approach, which poses issues. Project-based approaches are inherently rigid and time-bound, while innovations necessitate time and flexibility. Furthermore, the discontinuous nature of projects impedes the effective utilization of the progressive learning curve essential for innovation development. This project-based approach creates an ongoing dilemma for suppliers, who face high risks and a lack of incentives to innovate, despite their pivotal role.

To bridge the gap between understanding and implementing innovations within infrastructure programme, this research aims to address the issue of ineffective innovation utilization in multi-project settings based on suppliers’ perspective. The research approach involves conducting three case studies where innovations are developed and implemented in multi-projects as part of infrastructure programmes. 11 suppliers, including engineering companies and contractors, were interviewed to identify the elements of innovation in multi-projects, including barriers and enablers.

The study reveals seven specific barriers and five enablers related to innovation in multi-projects within infrastructure programs. Notably, it highlights the previously overlooked challenges related to time in innovation, arising from prolonged processes and programme durations. The primary innovation challenge in multi-projects revolves around technical challenge, tied to iterative processes and uncertainty management, irrespective of the type of innovation. These challenges, inherent to innovation, emphasize the need to strike a balance where time supports rather than impedes innovation. The study also confirms known barriers and enablers from project literature. With the choice of a suitable contract form, such as framework or alliance contracts, emerges as a significant enabler. However, contracts can become barriers when they lack risk-sharing mechanisms and still promoting competition, hindering knowledge exchange with external parties. Client-related barriers include the client’s organization size/structure and clients’ inflexible demands. Additionally, the study identifies drivers, inputs, preconditions, outputs, and outcomes of innovations in multi-projects. Preconditions unique to multi-projects include strong organizational leadership, vision, commitment to innovations, financial capabilities, and the selection of an appropriate contract form. Beyond the typical inputs, suppliers stress the importance of certainty regarding the volume of work or the number of projects within multi-projects.

Based on research findings, a solutions framework was developed to facilitate the implementation of innovations in multi-projects. It consists of practical action plans and innovation boundaries designed to address barriers to innovation in multi-projects. Suppliers and public client organizations are recommended to use the Innov-Infra framework during project/program initiation (Part I) and project/program implementation (Part II), led by a designated person within the organization involved in multi-project innovations. Future research should explore public clients' perspectives in similar research across various programme types and sectors, employing qualitative research methods to delve deeper into procurement for innovations and the bundling of supply and demand in contracts.