This research has explored the potential of segmentation and segmented contracting as a solution for managing the complexities of infrastructure projects in the Netherlands. As the country's civil infrastructure ages, innovative approaches are required to address the extensive challenges of renewal and renovation that lie ahead. This study has examined the benefits, challenges, and key considerations of segmented contracting, providing a comprehensive understanding for clients and contractors. The research has begun by reviewing various project delivery methods, including traditional, integrated, and co-contracting approaches, to establish a theoretical foundation. It has then analysed how segmentation is applied in current and recent projects, identifying its impact on project complexity and potential solutions. A segmentation framework has been developed to guide the application of segmented contracting. The framework demonstrates the impact of horizontal and vertical segmentation on project complexity elements. Additionally, a typology of segmented project delivery methods has been introduced, categorising approaches such as the segmented traditional project delivery method, the segmented integrated project delivery method, the segmented design team (2.0) project delivery method, and the segmented two-phase project delivery method. Expert insights have been incorporated to validate the findings and provide strategic approaches for effective implementation of segmented contracting. Segmentation, segmented project delivery methods, and segmented contracting offer several solutions to address complexity elements in complex infrastructure projects. By breaking down projects into smaller, manageable segments, clients and contractors can allocate resources and expertise more effectively, tailor risk management strategies, and maintain better control over budgets and schedules. This approach facilitates specialised focus on specific tasks, enhances project manageability, and improves the predictability of project outcomes. However, segmentation also introduces significant challenges, requiring robust coordination, communication, and integration efforts. Without these, projects may face inefficiencies, increased risks, and potential delays. Ultimately, this research has aimed to enhance industry practices, improve market competition, and support the civil engineering sector in addressing the significant infrastructure renewal and renovation challenges ahead. The findings have offered both practical and theoretical insights, promoting better management and fostering a more resilient and adaptive built environment.

The Dutch construction industry faces the recurring issues related to delays and conflicts, resulting in adverse effects on construction projects. Researchers have proposed pain/gain sharing mechanisms as a potential solution to address these issues. However, there is a gap between theoretical suggestions and practical implementation. This empirical study aims to bridge this knowledge gap by investigating the practical implementation of pain/gain sharing mechanisms in the Dutch construction industry. The objective is to explore how these mechanisms can provide value to contractors.

The literature review reveals that the NEC4 contract ECS4 Option C is commonly used for implementing pain/gain sharing mechanisms. Additionally, secondary option clauses such as Option X6 (bonus for early completion) and Option X20 (key performance indicators) are identified. While these mechanisms have primarily been applied in alliances or client-contractor relationships, they can also be adapted for contractor-subcontractor relationships.

Through in-depth analysis of three case studies and eleven semi-structured interviews, it is found that essential conditions for successful pain/gain sharing mechanisms are often missing. Transparency, aligned objectives, consideration of each other's interests, and early involvement of parties are identified as crucial factors for success.

To address the identified gaps in the implementation process, a comprehensive framework is developed, which is well-received by industry experts. The framework aids in selecting the most suitable pain/gain sharing mechanism and ensuring all parties understand its benefits and implications. Two options, an escape plan or commitment to the mechanism, are proposed to provide flexibility.

The developed framework enhances the understanding and implementation of pain/gain sharing mechanisms in the construction industry. By respecting and guaranteeing agreements, the optimal effectiveness of these mechanisms can be realized. This research contributes to bridging the gap between theoretical suggestions and practical implementation, paving the way for more successful construction projects in the Dutch construction industry.