Modelling effort in the process industry has traditionally focussed on the development, implementation and solution of the actual flowsheet or unit operation based models, i.e. the equations to use and package to solve them. This paper describes research that concentrates on how to model the higher level design processes and tasks that use these models as part of their implementation. The operation of a tool to aid one such process, Pressure Relief and Blowdown Studies, is illustrated. The generic design and use of novel Agent Based software technology to.