Project delivery in the German construction industry is strongly shaped by phase-oriented structures. Although the HOAI is not a project management method, its service phases are often used in practice to structure planning tasks, approvals, responsibili-ties and handovers. This provides orientation and transparency, especially in projects with clear requirements and stable conditions. However, many construction projects do not follow a strict linear process. Infrastructure projects, public projects, renovation works and technically complex buildings are often characterized by uncertainty, inter-face problems, late changes and parallel coordination. This thesis examines which requirements and opportunities flexible, agile and holistic project approaches offer in construction and how they can complement a HOAI-oriented project structure. Agile approaches are not understood as a replacement for the HOAI, but as additional elements that can improve communication, feedback, coor-dination and change management. The study combines a literature review with nine semi-structured expert interviews from different areas of construction practice, including client organizations, project manage-ment, architecture, specialist planning, renovation and infrastructure projects. The inter-views were analyzed using qualitative content analysis. The results show that the HOAI service phases are still regarded as an important struc-tural framework. Their limits become visible when phases are applied too rigidly. Infor-mation losses, incomplete handovers, unclear decisions and late changes often occur at the interfaces between clients, planners, authorities, contractors and project man-agement. Flexible elements such as regular coordination meetings, workshops, shorter decision cycles, digital task boards, BIM-based collaboration and early involvement of key participants can help to identify open issues earlier and improve coordination. The thesis concludes that future-oriented construction project delivery requires a hybrid approach: the HOAI service phases remain a useful basic structure, but they should be complemented by flexible, iterative and collaborative elements where uncertainty, change and interfaces are particularly significant.      «

Project delivery in the German construction industry is strongly shaped by phase-oriented structures. Although the HOAI is not a project management method, its service phases are often used in practice to structure planning tasks, approvals, responsibili-ties and handovers. This provides orientation and transparency, especially in projects with clear requirements and stable conditions. However, many construction projects do not follow a strict linear process. Infrastructure projects, public proj...     »