With　the　advancement　and　widespread　adoption　of　cloud　computing　technology,　Software　as　a　Service　(SaaS)　has　become　increasingly　common　as　a　software　service　model,　bringing　along　significant　uncertainties　in　performance.　The　ambiguous　performance　issues　surrounding　SaaS　application　software　have　garnered　considerable　attention.　Compared　to　probability　theory,　which　focuses　on　the　randomness　of　event　occurrences,　This　paper　proposes　an　innovative　approach　to　performance　modeling　and　analysis　using　possibility　theory,　which　focus　on　the　degree　of　trustworthiness　in　fuzzy　performance　assertion.　A　typical　preliminary　experimental　case　validated　the　feasibility　of　our　method.　©　2024　IEEE.