Enhanced Time‐Expanded Decision Network: The Original TDN and More

This paper suggests several improvements over the original Time‐expanded Decision Network (TDN; a powerful and generic methodology introduced by Silver and de Weck for designing evolvable complex systems) in order to leverage its ease, flexibility, and scope of use. A more accurate model of the switching process, a simpler network representation, and the ability to address systems with unknown lifetime are some of the improvements. However, the most important added feature is the ability to account for other design requirements within the process, which enables the designers to embed the TDN methodology into their general concept exploration phase. As a result, the enhanced TDN (ETDN) mitigates the need for iterations over several requirement domains and makes achieving the optimal design easier. It is also discussed in the paper that all of the improvements are attained without adding to the original method's complexity and only by a marginal increment of computational costs. As an example, the design of a sports car system is described and all of the new features are applied and the results are thoroughly discussed—although the example's focus is solely on the new improvements and not on the features that are directly inherited from the original method.