Learn in the textbookPhysical Security Measures
DefinitionLock management means keeping rooms and storage locked so that only authorized people holding the key can open them.
ExplanationBeyond locking up, it records who borrowed a key and when, when it came back, and how many spare keys exist. Measures like this that protect places and things are called physical measures (物理的対策). They are distinct from human measures (人的対策), which work on people through contracts and training, and technical measures (技術的対策), which protect through authentication, encryption and the like.
AnalogyIt is like never handing your front-door key to anyone outside the family and knowing exactly who holds the spares.
Memory hook"Lock" is the act of locking; "management" is tracking where the keys go. Only both halves together make up the measure.