The objective of this paper is to discuss and elaborate on requirements of maintenance and the resulting maintenance needs in order to maintain said requirements without introducing waste while doing so, taking into account both external and internal wastes. The paper will present, and elaborate on, conceptual models that can be utilized in maintenance operations in order to increase awareness of the importance of well-founded customer/stakeholder requirements in order to articulate appropriate maintenance needs in order to balance effectiveness and efficiency as well as to reduce or eliminate maintenance-related waste.