A method for installing function monitoring means in a flow machine installation, wherein the function monitoring means are formed by at least one thermochromic paint, and wherein the method comprises: selecting at least one component of the flow machine installation whose function is to be monitored; selecting a predetermined thermochromic paint for the component whose function is to be monitored; applying the thermochromic paint on the component whose function is to be monitored; and wherein the thermochromic paint is applied to at least one component of the flow machine installation, which component is to be monitored with respect to the through-flow of process fluid therein.