In the Dutch building sector, and in the social housing sector in particular, supply chain collaboration between housing associations and their supply chain have been quite popular since last five years or so. Many associations and their supply chain partners have tested, and in many cases continued to apply various representations of supply chain collaboration. This has varied from newly built houses to maintenance of existing stock, and many other characteristics influencing the collaboration. In all cases the parties involved have aimed and hoped for better performance of projects as a consequence of applying supply chain collaboration. Two main issues have arisen amongst the associations and their supply chain partners: How do various representations of supply chain collaboration applied by different parties relate to each other characteristically? How does supply chain collaboration in projects of different kinds influence the performance outcomes of these projects, and thus give evidence of the appropriateness and effectiveness of supply chain collaboration. Therefore a supply chain monitor has been developed as an instrument to assess the levels of the resources and processes in projects, versus the performance outputs and outcomes of these projects. This paper presents the background, purpose, development and structure of the supply chain monitor and compares it to other models, in order to discusses the internal validity and usefulness of the monitor to characterise supply chain collaboration and measure its effectiveness in projects.