An ILS plan is comprehensive documentation that outlines the strategies, activities, and resources needed to support a system or product throughout its lifecycle. ILSP provides a roadmap to effectively manage the ILS activities that need to be done at all phases of the life cycle (Pre-Concept) to the end of the life cycle (Disposal) and to ensure the availability and maintenance of the system/product. Since it is a large document, it mostly consists of sub-plans such as Maintenance Plan, Reliability Maintainability Plan, Training Plan, Technical Documentation Plan.
ILSP acts as a guide for coordinating and executing ILS activities throughout the life cycle of a system or product. It ensures that all necessary support elements are taken into account, resources are used effectively, and ILS goals are achieved.