The development of a global model incorporating Climate, Land, Energy and Water (CLEW) parameters and interconnections was undertaken using the Open Source Energy Modelling SYStem. The model was to be a simplistic representation of the nexus systems and include the most relevant mechanisms between them. Two separate modules on land use and materials were created and combined with an already existing energy module. Water and climate parameters were added to all modules and they were combined to the global CLEWs Base model. Three scenarios were run on the separate sector modules and the combined model. Results from the comparison of the separate and combined modules indicate that the CLEW approach is applicable even on a simplistic, highly aggregated scale. Differences in resource allocation were observed when the same parameters were run in the single sector modules and in the combined base model. However, to make the model provide a representative image of global resource conditions additional data and parameters will be required. The resulting global CLEWs model provides a wide range of potential applications and can be easily expanded. As an open source tool it could act as an educational instrument or for policy support and be adapted to different geographical boundaries and detail.

Enterprise modelling can facilitate the design, analysis, control and construction of contemporary enterprises which can compete in world-wide Product markets. This research involves a systematic study of enterprise modelling with a particular focus on resource modelling in support of the life cycle engineering of enterprise systems. This led to the specification and design of a framework for resource modelling. This framework was conceived to: classify resource types; identify the different functions that resource modelling can support, with respect to different life phases of enterprise systems; clarify the relationship between resource models and other modelling perspectives provide mechanisms which link resource models and other types of models; identify guidelines for the capture of information - on resources, leading to the establishment of a set of resource reference models. The author also designed and implemented a resource modelling tool which conforms to the principles laid down by the framework. This tool realises important aspects of the resource modeffing concepts so defined. Furthermore, two case studies have been carried out. One models a metal cutting environment, and the other is based on an electronics industry problem area. In this way, the feasibility of concepts embodied in the framework and the design of the resource modelling tool has been tested and evaluated. Following a literature survey and preliminary investigation, the CIMOSA enterprise modelling and integration methodology was adopted and extended within this research. Here the resource modelling tool was built by extending SEWOSA (System Engineering Workbench for Open System Architecture) and utilising the CIMBIOSYS (CINI-Building Integrated Open SYStems) integrating infrastructure. The main contributions of the research are that: a framework for resource modelling has been established; means and mechanisms have been proposed, implemented and tested which link and coordinate different modelling perspectives into an unified enterprise model; the mechanisms and resource models generated by this research support each Pfe phase of systems engineering projects and demonstrate benefits by increasing the degree to which the derivation process among models is automated.