Vector dimensions and drawing engineering plans is the first and most effective step in segments reverse engineering. According to the shape and sensitivity of the piece, the type of studied dimensions, the method of foundation, the surface conditions of the part and the functional requirements, the desired tool is selected for the vector dimensions. Various tools and equipment such as calipers, micrometers, microheats, CMMs and digitizers can be used for vector dimensions. In order to draw engineering plans, there must be the necessary technical knowledge and expertise in determining limit and engineering tolerances. The correct estimation of the interaction and orthogonality of the segments with each other in a set, is achieved with the help of tolerance technical knowledge. In Naftan Payesh Company, all drawings are drawn according to valid international standards, in a way that can be understood and executed by any contractor.