This paper presents a detailed description of a model-independent method for the direct measurement of the Υ(4S) → B⁺ B⁻ and Υ(4S) → B⁰ B̄⁰ production fractions at B factories. The method is based on counting single- and double-inclusive charmed meson production at the Υ(4S) resonance, providing statistical tagging of B⁰B̄⁰ and B⁺B⁻ events. A feasibility study indicates that a precision comparable to the current world average can be achieved without making any underlying assumptions, as the calculations rely solely on event yields.