Engineers analyze tolerances for the purpose of evaluating geometric dimensioning and tolerancing (GD&T). Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances. Several systems of dimensioning and tolerancing have evolved. Such a view might be desired for calculating clearances or for dimensioning purposes. Because of the complexity of network dimensioning, this is typically done using specialized software tools. There are various technologies used in dimensioning devices varying from point distance sensors to 3D-cameras. It is easy to draw ducts in 3D without correct dimensioning. Since then, automated dimensioning solutions produced by different manufacturers have come to market. All the dimensioning of the elements was done in accordance with European and Yugolsav codes. Users can quickly and easily complete dimensioning of wall, door, window, stair, etc. It also stated that C-DOT had finalized the "scope, architecture and dimensioning of the network". The Finnish-Swedish ice class rules of 1985 introduced changes to the hull dimensioning. It is generally used when dimensioning and for laying out with the grain. ASME Y14.5 is a complete definition of Geometric Dimensioning and Tolerancing. It is complemented by ASME Y14.5.1 - Mathematical Definition of Dimensioning and Tolerancing Principles.