An ecosystem perspective of programme commercial strategy: the case of railway infrastructure renewal in Denmark from 1991–2024

• Programmes depend on a healthy ecosystem of project-based firms over time. • The structure of the programme has an influence of the health of the market. • Ecosystems theory gives insight into the interaction of programme structure and supplier market. • Programme ecosystem strategy considers the creation and maintenance of temporary ecosystems. Major programmes have an inherent co-dependence on the health of the market of project-based firms that are often crucial in the realisation of the programme. While considerable research exists on bilateral commercial relationships in construction, this research aims to gain a greater understanding of how programme commercial strategy influences the broader ecosystem of project-based firms. This paper makes a longitudinal case study of the national railway infrastructure renewal programme in Denmark from 1991 to 2024 to understand how the ecosystem has developed over time. The theoretical lens of business ecosystems gives insight into the influence of programme commercial strategy on the health of the market of suppliers. The findings demonstrate the importance of lifecycle, rate of growth, cospecialisation and packaging of projects in the development of programme commercial strategy. The paper concludes by proposing programme ecosystem strategy as an extension of programme commercial strategy which takes greater account of the influence of the programme at the ecosystem level.