Before you determine the dimensions of a project, your design is in flux, and many questions might be unanswered. After you begin dimensioning, you will begin to see whether things fit or work together. Dimensioning can be crucial to how well a design works and how quickly it develops. The dimensions answer questions about code conformance if you are an architect; they answer questions about tolerances, fit, and interference if you are involved in mechanical applications. After you and your design team reach a design on a schematic level, communicating even tentative dimensions to others on the team can accelerate design development. Dimensions represent a point from which you can further develop your ideas.
With AutoCAD, you can easily add tentative or final dimensions to any drawing. AutoCAD gives you an accurate dimension without your having to take measurements. You simply pick the two points to be dimensioned and the dimension line location, and AutoCAD does the rest. AutoCAD's associative dimensioning capability automatically updates dimensions whenever the size or shape of the dimensioned object changes. These dimensioning features can save you valuable time and reduce the number of dimensional errors in your drawings.