Definition (1):
Line of effort— in the context of joint operation planning, using the purpose (cause and effect) to focus efforts toward establishing operational and strategic conditions by linking multiple tasks and missions. Also called LOE. This abbreviation is vastly used in various industries such as computing, banking, finance, educational, governmental, health, and military.
Definition (2):
A line of effort can be defined as a line that "links multiple tasks and missions using the logic of purpose—cause and effect—to focus efforts toward establishing operational and strategic conditions."
This term is mainly used in the military vocabulary of the United States. The Department of Defense in the United States standardized this vocabulary. The United States Navy, Army, Marine Corps, and Air Force use this term. Officers initially responsible for the line of operations develop (line of efforts) LOEs within their certain line of operations for creating synergy for a durable campaign and for providing linkage between the present and future operations. They code each LOE with different colors in their military plan to differentiate among tactical, strategic, and operational conditions and to focus on the efforts depending on the operations level.