FEDIS is a high advanced FE submodelling tool for all intents and purposes. 

• Easy modelling of submodel (free mesh subdivision and element type)
• Stress accuracy is the same as a continously fine overall model
• Computing times remain very short; iterative equation solvers are particularly efficient
• With the transition from an overall model to a submodel any changes can be made in terms of element topology (shape of elements and order of polynomial Ansatz functions).
• FEDIS special capabilities enable transitions from "lower-quality" to "higher-quality" elements.