This paper dissects the complex and multifaceted planning of Operation Overlord, and examines how the operational structure, viewed as a comprehensive entity, through the theoretical lens of Castex’ strategic maneuver, could be conceptualized. The existing body of research, as it pertains to the planning of Operation Overlord, persistently overlooks the ability of theoretical synthesization to generate a more comprehensive understanding of the phenomenon. Thus, while framing Castex’ strategic maneuver as a simplification of reality, this qualitative case study analyzes the planning and preparatory activities of the Western Allies concerning the cross-channel invasion of Continental Europe in 1944, in order to deepen the understanding of how a large-scale, amphibious operation was planned and structured. The analysis identifies several operational aspects of planning, which, when integrated with the theoretical framework of the strategic maneuver, yields a traceable, and coherent comprehension of the operational reasoning. The results of the analysis illustrates the procedural deconstruction of an intricate operation by structurally reorganizing it into the five components and three subcomponents of the strategic maneuver, rendering it more comprehensible and transparent. This refined operational framework clarifies the previously complex planning process, which consequently promotes a more procedural conceptualization of how this large-scale amphibious operation was planned.