In this paper we advance the development of our python-based package for the solution of partial differential equations using spatial discretization techniques such as the finite element method (FEM) via two approaches. First we define a Model class object which makes it easy to break down a complex simulation into simpler sub-models, which then can be linked together into a highly efficient whole. Second, we implement an XML schema in which we can save an entire simulation. This allows implemention of check-pointing in addition to graphical user interfaces which enables non-programmers to use models developed for their research. These features are built upon our escript module, a software package designed to develop numerical models in a very abstract way while still allowing the use of computational components implemented in C and C++ to achieve extreme high-performance for time-intensive calculations.