Electrical propulsion has been identified as a key enabler of greener, quieter, and more efficient aircraft. However, electrical propulsion aircraft (EPA) will need to demonstrate a level of safety and reliability at least equal to current aircraft to be a viable alternative. Therefore, a robust and reliable fault management (FM) system is needed to prevent electrical faults causing loss of propulsion and critical flight functions. To date, FM of the electrical propulsion system has not been considered in detail for future EPA, nor has it been effectively integrated into the electrical architecture design. This poses a risk that the proposed electrical architectures will be infeasible from an FM perspective, and key FM technologies may not be sufficiently developed. Therefore, a methodology to incorporate FM into the early stages of the design of electrical architectures is required to determine viable FM solutions for a given EPA concept. This paper describes a novel, system-level electrical architecture design framework for EPA, which incorporates FM from the outset. This methodology captures the significant assumptions in the design and acknowledges the novel interfaces that exist between the electrical, conceptual, and FM design of EPA.