A method for supporting an operator in measuring a part of an object, comprising the steps of: • Equipping said operator with an electronic device comprising a see through head mounted display, at least a camera, and a digital processor; and with a dimension measuring apparatus being a slide calliper, a micrometer, a height gauge, a tape rule, a Go/no go gauge, a coordinate measuring machine, an arm of a coordinate measuring machine, a part of a coordinate measuring machine, a laser tracker or an optical measuring instrument; • Capturing an image of said object with said at least a camera; • In the image, recognizing and/or identifying with the processor said part of the object to be measured; • Obtaining a model of said part and displaying a representation of the model on the see-though head mounted display; • Displaying on the display an indication of the dimension that is intended to be measured, wherein a mark is displayed in order to indicate a surface of the object or extremities of the part of the object that have to be measured by means of said dimension measuring apparatus; • Acquiring in the processor a value of the dimension of said part of the object measured by the dimension measuring apparatus; wherein said step of acquiring comprises a step of: transmitting digital data from the dimension measuring apparatus to the processor via a data link; or capturing an image of an analogue display or indication of the dimension measuring apparatus in order to recognize or identify the indicated analogue value, and converting the captured image into a digital value within the processor; • Processing said value based on tolerances values of said part of the object and/or of the object that are provided by the model and displaying an outcome of said processing on the see through head mounted display. • Equipping said operator with an electronic device comprising a see through head mounted display, at least a camera, and a digital processor; and with a dimension measuring apparatus being a slide calliper, a micrometer, a height gauge, a tape rule, a Go/no go gauge, a coordinate measuring machine, an arm of a coordinate measuring machine, a part of a coordinate measuring machine, a laser tracker or an optical measuring instrument; • Capturing an image of said object with said at least a camera; • In the image, recognizing and/or identifying with the processor said part of the object to be measured; • Obtaining a model of said part and displaying a representation of the model on the see-though head mounted display; • Displaying on the display an indication of the dimension that is intended to be measured, wherein a mark is displayed in order to indicate a surface of the object or extremities of the part of the object that have to be measured by means of said dimension measuring apparatus; • Acquiring in the processor a value of the dimension of said part of the object measured by the dimension measuring apparatus; wherein said step of acquiring comprises a step of: transmitting digital data from the dimension measuring apparatus to the processor via a data link; or capturing an image of an analogue display or indication of the dimension measuring apparatus in order to recognize or identify the indicated analogue value, and converting the captured image into a digital value within the processor; transmitting digital data from the dimension measuring apparatus to the processor via a data link; or capturing an image of an analogue display or indication of the dimension measuring apparatus in order to recognize or identify the indicated analogue value, and converting the captured image into a digital value within the processor; • Processing said value based on tolerances values of said part of the object and/or of the object that are provided by the model and displaying an outcome of said processing on the see through head mounted display.