Design for Excellence (DfEx) is the name given to an engineering process where a product is designed to meet a set of objective functions that cover its lifecycle. There are negative correlations between different objective functions in this set and issues related to technological complexity are added, since modern products typically fall into the category of smart connected mechatronic products. This context leads to complexity in terms of tackling the design process. Simultaneous engineering and PLM platforms can only partially handle such levels of complexity. To our knowledge, the subject of DfEx was treated in current researches from a limited perspective, which does not necessarily cover the complexity of the present-day context. In order to formulate a reliable DfEx framework, this research considers a strategy based on tools that manage in a systematic way the process of identifying the comprehensive set of barriers and conflicts that obstruct DfEx. This research highlights the level of complexity in setting up a reliable methodology to DfEx of modern, sophisticated mechatronic products. A set of guidelines to be placed at the foundation of an effective DfEx methodology is formulated with the support of TRIZ.