Warm　standby　is　an　energy-saving　redundancy　technique　that　consumes　less　energy　than　a　conventional　hot　standby　method.　It　can　be　naturally　integrated　with　an　energy　storage　technique　to　enhance　system　reliability.　However,　the　integration　approach　of　both　techniques　and　the　advantage　it　affords　to　system　reliability　have　not　been　reported　in　literature.　This　study　resolves　this　limitation　by　formulating　a　novel　reliability　model　for　demand-based　warm　standby　systems　with　capacity　storage.　In　this　model,　the　chronological　characteristics　of　warm　standby　components　are　explicitly　explored　before　and　after　their　activation.　Moreover,　different　utilization　sequences　of　warm　standby　components　and　storage　components　are　embedded　to　analyze　the　effects　of　these　sequences　on　system　reliability.　A　multi-valued　decision　diagram　is　developed　to　evaluate　system　reliability　considering　successful　activation　probabilities　of　warm　standby　components.　This　diagram　is　applicable　to　arbitrary　component　lifetime　distributions　and　warm　standby　systems.　Numerical　examples　are　presented　to　verify　the　application　of　the　proposed　methodology.