A stage (50; 150; 250; 350; 450) of a gas turbine engine , comprising: a row of flow directing components (52; 152; 252; 352; 452) circumferentially disposed about a centerline axis (A) and each comprising a respective airfoil; and at least one flow directing component (52;...452) of said row having at least one design characteristic (D) that is dissimilar from a corresponding design characteristic (E) of at least one other flow directing component (52;...452) of said row; characterised in that : said at least one design characteristic (D) is one of: an airfoil pitch; an inner platform endwall contour (55-1), wherein the inner platform endwall contour (55-1) includes at least one undulation comprising a peak and a valley , the peak directly adjoining a pressure side of the airfoil adjacent to a leading edge of the airfoil, and the valley directly adjoining a suction side of the airfoil aft of the leading edge ; or both said inner platform endwall contour (55-1) and an outer platform endwall contour (55-2), wherein one of the inner platform endwall contour (55-1) or the outer platform endwall contour (55-2) includes at least one undulation comprising a peak and a valley , the peak directly adjoining a pressure side of the airfoil adjacent to a leading edge of the airfoil, and the valley directly adjoining a suction side of the airfoil aft of the leading edge . a row of flow directing components (52; 152; 252; 352; 452) circumferentially disposed about a centerline axis (A) and each comprising a respective airfoil; and at least one flow directing component (52;...452) of said row having at least one design characteristic (D) that is dissimilar from a corresponding design characteristic (E) of at least one other flow directing component (52;...452) of said row; characterised in that : said at least one design characteristic (D) is one of: an airfoil pitch; an inner platform endwall contour (55-1), wherein the inner platform endwall contour (55-1) includes at least one undulation comprising a peak and a valley , the peak directly adjoining a pressure side of the airfoil adjacent to a leading edge of the airfoil, and the valley directly adjoining a suction side of the airfoil aft of the leading edge ; or both said inner platform endwall contour (55-1) and an outer platform endwall contour (55-2), wherein one of the inner platform endwall contour (55-1) or the outer platform endwall contour (55-2) includes at least one undulation comprising a peak and a valley , the peak directly adjoining a pressure side of the airfoil adjacent to a leading edge of the airfoil, and the valley directly adjoining a suction side of the airfoil aft of the leading edge . an airfoil pitch; an inner platform endwall contour (55-1), wherein the inner platform endwall contour (55-1) includes at least one undulation comprising a peak and a valley , the peak directly adjoining a pressure side of the airfoil adjacent to a leading edge of the airfoil, and the valley directly adjoining a suction side of the airfoil aft of the leading edge ; or both said inner platform endwall contour (55-1) and an outer platform endwall contour (55-2), wherein one of the inner platform endwall contour (55-1) or the outer platform endwall contour (55-2) includes at least one undulation comprising a peak and a valley , the peak directly adjoining a pressure side of the airfoil adjacent to a leading edge of the airfoil, and the valley directly adjoining a suction side of the airfoil aft of the leading edge . <EOS>