Computer applications for engineering design evolve rapidly. Many design frameworks were developed by the simulation based systems so that organizations could achieve significant benefits due to cost reduction in designing. However, today’s transient design issue requires being adaptable to more complicated and atypical problems. In this paper the Multidisciplinary Language Runtime (MLR) design framework is developed. The MLR provides flexible and extensible interface between analysis modules and numerical analysis codes. It also supports Meta Modeling, Meta Variable, and XML script for atypical design formulation. By applying object-oriented design scheme to implement abstractions of the key components required for iterative systems analyses, the MLR provides flexible and extensible problem-solving environment.