There is no knowledge about connecting an engine to an existing chess frontend. Available open source engines are programmed in C and are delivered as executable programs (*.exe). Since DokChess is developed in Java, they are of limited use as examples. Nothing is known in the project about chess communication protocols.
If it is not possible to make a working connection, the solution can not be used with existing frontends. This not only lacks an important feature (→ 1.1 Requirements Overview), but also makes the solution as a whole, especially as a case study, untrustworthy.
A simple textual user interface could be implemented in order to interact with the engine. The implementation of a DokChess specific graphical front end would be costly (→ 11.2 “Effort of Implementation”).
Through an early proof of concept, certainty is achieved as soon as possible here.