Intensified EU CO2 regulations for heavy-duty trucks until 2030 are driving significant advancements in electrified powertrains (eDrives) in this segment. Currently, the market shows no definitive trends regarding drivetrain topologies. This refers to systems such as eAxels or central drive topologies, as well as to specific parameters like the number of eMotors, gear modes, and gear stages. Unlike the passenger car industry, the truck sector operates with smaller production volumes, prompting OEMs to strive for optimal portfolio coverage through powertrain platform strategies. Thereby, development departments need to consider diverse vehicle requirements by weighting the corresponding vehicle application importance. Moreover, the conflicting goals of minimizing the number of platform components and optimizing the powertrain efficiency of each portfolio vehicle must be evaluated. This paper provides an overview of current powertrains for heavy-duty trucks and examines the development process of an eDrive system, using Daimler Truck as an example. Additionally, a methodological approach for an automatic design of a powertrain platform for electrified trucks is proposed. Key steps include portfolio analysis, power level definition, variation of powertrain components, and overall powertrain optimization. The variation of components is realized by adjusting and varying parameters e.g. number of eMotors and gear modes, and number of teeth or widths of gears in the transmission.