1. A system for generating a performance index to quantify operating transition performance of a continuous process line that is carried out by a grade change control comprising: a database adapted to store at least one performance parameter stored thereon that is associated with an operating transition carried out by the grade change control during a transition time period; and a computer system coupled to said database, said computer system configured to generate a transition performance index based on said at least one operating parameter, wherein said transition performance index is derived from at least two performance indices selected from the group consisting of a transition time index, a sheet weight ramp index, a sheet weight change index, a line speed change index, a steam prediction error index, and a moisture deviation index, and wherein said at least two performance indices are weighted by a weight value.