Abstract: A method for correcting errors on a work piece comprising the steps of defining a compensating rectangle, inputting the actual rectangle and obtaining and applying the compensating values that satisfy the actual coordinate system. A compensating rectangle is a rectangle inside a work piece with one side parallel to one axis of a machine coordinate, three or four points being required to define the compensating rectangle. An actual rectangle is a rectangle inside a work piece, the four corner points being the actual or estimate reading values obtained from inspection of the compensating rectangle. The coordinate system values are the numbers that can be applied to a point to move it from one location to a different location in one coordinate system. The corner points of the compensating rectangle are moved so that they best fit the corner points of the actual rectangle.