Development of Multi-Framework Model Components

A number of environmental modelling frameworks have been developed recently, and plans for new frameworks are under way. Examples such as TIME, OpenMI, SME and OMS share an approach to environmental modelling based on model components, and offer improved model development and deployment. These approaches have methods for ensuring model component-linking compatibility using manual and machine processes either internal or external to the model component. Examples include matching output to input and checking data type compatibility. Semantic integration is also possible, such as with the OpenMI, where a component requests and receives particular data. However, each framework does model component checking in a different way and interoperability between model components of different frameworks is limited. To improve the use of model components it is necessary to consider the development of multi-framework model components (MFMC). Existing software standards enable communication at a low level, but many problems remain at high levels. This paper discusses development of an MFMC in each of TIME and the OMS, that can be accessed from the other framework. Additionally, the requirements for further framework compatibility, such as the OpenMI, are considered. Six main approaches are described, covering methods relevant to both betweenand cross-platform compatibility, which range from reimplementation, through Web Services, to declarative modelling. Web services are suggested as a viable option for the problem considered here, although the other techniques warrant further investigation in particular cases.