An　interval-parameter　integer　non-linear　programming　(IPINP)　model　is　developed　for　the　assessment　of　filter　allocation　and　replacement　strategies　in　a　hydraulic　contamination　control　system　under　uncertainty.　The　IPINP　can　handle　uncertainties　expressed　as　interval　values　that　exist　in　the　left-　and　right-hand　sides　of　constraints　as　well　as　in　the　objective　function.　A　piecewise　linearization　approach　is　proposed　to　solve　the　IPINP　model,　which　has　advantages　in　identifying　global　optimum　and　is　associated　with　low　computational　efforts　for　an　uncertain　non-linear　programme.　The　developed　method　has　been　applied　to　a　case　of　planning　filter　allocation　and　replacement　strategies　under　uncertainty　for　a　fluid　power　system　(FPS)　with　a　single　circuit.　Three　different　contaminant　ingression/generation　rates　are　examined　based　on　several　filter-installation　scenarios.　The　combination　of　low-costing　suction　and　return　filters　exhibits　excellent　contaminant　resistibility　along　with　the　optimum　replacement　periods　of　filter　elements　and　operation　costs　under　the　low　and　medium　contaminant　ingression/generation　level.　The　solutions　can　be　used　for　generating　a　range　of　decision　alternatives　and　thus　help　the　decision-makers　to　identify　desired　filter　allocation　and　replacement　plan　with　a　minimized　operation　cost　and　a　minimized　system-failure　risk　for　FPS.