IntroductionWar believes that success and failure are inevitably linked to how the combined, joint and multinational commander ensures that the "support" function of the function of joint combat links to strategic, operational and tactical objective links. General Eisenhower's Operation OVERLORD, the Allied cross-Channel, air and sea invasion of France during World War II, provides an excellent case study to demonstrate the successful integration of the principles and spirit of the joint function fighter of the war "Support". OVERLORD required the synchronization, coordination and integration of the logistical capabilities of coalition forces and their equipment, as well as civilian manufacturing capabilities to meet the political end state (e.g. the defeat of Germany). This article will examine the purpose and definition of joint support; its logistics planning imperatives and principles; and examine how Eisenhower and his planners incorporated these imperatives and principles into Operation OVERLORD. Joint Sustainment, Principles and Imperatives Joint Publishing 3.0 Joint Operations, is the provision of logistics and personnel services necessary to maintain and prolong operations through mission completion and force redeployment. Joint Publication 4-0 also states: “Effective joint logistics planning identifies future requirements and proposes solutions; requires joint logisticians to understand the commander's intent and concept of operations (CONOPS).” Logisticians use seven principles in their planning at the strategic, operational, and tactical levels of warfare to ensure that operations are logistically supportable and sustainable throughout the duration of operations. These principles are survival, responsiveness, economy, achievement...... middle of paper ......om/misc/images/5/ WWII_Mulberry_harbour.jpg. Accessed March 25, 2014. JP 4-0, xvi. FA Osmanski, The logistical planning of Operation OVERLORD, Military Review vol. XXIX No. 8, (November 1949), accessed at http://cgsc.contentdm.oclc.org/cdm/ref/collection/p124201coll1/id903 (accessed 23 October 2013) p.41. Krysa, John C., Operational Planning in the Normandy Campaign, 1944, p.25-26. The ships were used as sorties to land forces on the beach and return to England for additional forces, supplies and equipment. Bowden, Mark, D-Day: June 6, 1944, 2002, p.5. The aviation industry built 800 planes in 1939 and reached 8,000 per month in 1943. Ibid., 21. JP 4-0, I-2. Matthew D. Cox, “Virtual Library Logistics: Logistics Quotations,” “Logistics World,” September 4, 1999. Accessed February 21, 2014), http://www.logisticsworld.com/logistics/quotations.htm.