Formalising a measurement is often preceded by rich discussion of the ideas, and the development of general understanding of the meaning of concepts, often over decades. As a consequence, data required to fit into a representational measurement system is usually readily available and there is a general acceptance of the intention of the measure. This paper reports on a research project which has formalised the measurement of a relatively new body of knowledge, open systems. Open systems rely on standards to guarantee interoperability, portability, scalability and user portability. The internet is the most successful of the open systems in existence, in terms of interoperability and scalability. The first of four issues was that since the project was a research contract, and because there were very few generally understood notions of measurement foundations (or relations) within open systems, the aims and the requirements of the measurement were formalised into a measurement requirements specification (MRS). A second issue concerns the building of a relational model. Building relations in a representational measurement model [9] is relatively straightforward in the case where the measurement entity has been around. A third issue concerned the use of the measures when the measures were (not surprisingly) complex, and had to be combined by biased combiners, the values of which not all parties would naturally agree. There needed to be an appeal to some stakeholder resolution principles to get any agreement, and this is undoubtedly a critical area for further research. A fourth issue raised in the paper is the extent of the validation of the measures [11] which was required because of the contract. The result is a solid, transparent measurement framework and base within which open systems experience can be captured and understood.