But simplicity, as a guiding principle in constructing conceptual schemes, is not a clear and unambiguous idea; and it is quite capable of presenting a double or multiple standard.

Graduate design students at Iowa State University have created conceptual schemes for shelters that would house us soldiers fighting in Afghanistan and help give them a sense of safety.

Evaluation and selection of conceptual design schemes are of importance in the procedure, so the index system of evaluation is built and then fuzzy optimization based decision model is discussed.