Splines are a powerful Sketch Entity often used in the creation of Consumer Products. Splines provide multiple ways in which they can be defined to get the desired size and shape. SolidWorks 2014 provides an additional parameter for those users who desire to control the overall length of a Spline by means of simply adding a Smart Dimension to any spline. This will create a Dimension that will drive the overall length of the spline giving users more control over it.
This is especially useful when wanting to control the overall length of geometry that is ultimately controlled by a Spline.
Also, because the Dimension is like any other Smart Dimension in SolidWorks it itself can be controlled by powerful Parametric tools such as equations.