It is well known that power transformers are regarded among the most important components in power systems networks. This clearly suggests that design, manufacturing and deployment of highly optimized and efficient transformer units are crucial for the minimization of the overall network capital cost and net losses. Moreover, power transformer manufacturers are facing increasing competitive cost and environmental challenges due to the industry market globalization. Those challenges are sometimes augmented by very specific design requests to accommodate special design specifications. This further highlights the importance of achieving power transformer design methodologies that can lead to meeting the required operational specifications.