Disclosed is a method and a system for measuring customer delivery service. The method for examining a foreign matter derived from a living body includes identifying an individual from whom a living body-derived material contaminated as a foreign matter in products or facilities involved in production of the products was derived, on the basis of information on sequences of nucleic acid contained in the living body-derived material. Each flexible strip is attached along at least one edge thereof to either the top or bottom surface of the airfoil body.