The use of Digital Twin (DT) is adopted by manufacturers and have positive effects on the product manufacturing process. The aim of this paper is to define a Coordinate Measuring Machine (CMM) inspection DT model, based on inspection process digitalized functionalities, from one side, and Industry 4.0 opportunities (Digital thread, Big data, etc.), from the other side. A review about DT definition, is firstly presented. Secondly, we review related studies based on existing DT orientations and usages for CMM inspection. Thirdly, challenges related to the variation management are presented. Finally, a discussion about possible DT functionalities and opportunities is conducted then a CMM inspection DT model is presented.