Performance　sharing　mechanism　is　widely　applied　in　energy　systems,　computing　systems　and　other　types　of　industrial　systems　to　increase　system　reliability.　In　reality,　some　systems　may　allow　certain　extent　of　performance　deficiency　instead　of　requiring　every　subsystem　in　the　system　satisfy　its　demand.　Moreover,　the　subsystems　in　systems　may　combine　with　amounts　of　components,　say　that,　a　series　of　generators　should　be　simultaneously　used　to　provide　the　necessary　energy　for　a　given　area.　In　this　paper,　we　consider　a　system　with　performance　sharing　mechanism　where　the　system　remains　functional　as　long　as　the　summed　weighted　deficiency　for　subsystems　after　performance　sharing　is　smaller　than　a　predesigned　reliable　threshold.　The　amount　of　shared　performance　is　further　assumed　to　restricted　by　the　bandwidth　capacity　of　the　system.　We　further　consider　the　case　where　the　surplus　can　be　redistributed　to　maximize　system　reliability.　Universal　generating　function　technique　is　employed　to　model　the　reliability　of　the　system　and　numerical　examples　are　provided　to　illustrate　the　applications.　©　Published　under　licence　by　IOP　Publishing　Ltd.