This paper is in the field of communication networks where different Electronic Control Units (ECUs) communicate with each other using various communication protocols such as Controller Area Network (CAN), Local Interconnect Network (LIN), FlexRay, etc. Typically such types of communication networks are widely used in automobile domain.This paper proposes a holistic approach for evaluation and finalization of complex network architecture for a vehicle. As part of this proposed method, at first one reference-network architecture is constructed for the highest end variant of the vehicle considering all possible ECUs for this vehicle. Then other possible logical variations in network architecture are constructed, which can also technically represent the vehicle's network architecture. Then a set of criteria measures are considered to evaluate how good (or bad) each variation of network architecture is with respect to the reference-network architecture. A detailed step by step methodology is proposed in this paper describing the various criteria and sub-criteria and the approach to finalize optimized network architecture for any vehicle.As the proposed method focuses on all possible aspects during network architecture evaluation; it results in minimization of network related ECU variants in the vehicle, both in terms of hardware and software content of the ECUs, thereby achieving standardization of vehicle communication matrix across all vehicle trim-levels. This standardization in network architecture leads to reduced engineering effort to design and develop any ECU in the vehicle.