1. A computer program product for providing semiconductor processing control, the computer program product having a non-transitory medium with a computer program embodied thereon, the computer program comprising: computer program code for providing a first data set for first measured results for a first parameter of processed wafers and a second data set for second measured results for a second parameter of the processed wafers, the first data set comprising first subsets, and the second data set comprising second subsets, each first subset and each second subset corresponding to one tool in a processing line, the processing line comprising multiple tools and multiple stages; computer program code for determining a first residual model and a second residual model for each first subset and each second subset, respectively; computer program code for determining a first residual vector and a second residual vector for each first subset and each second subset, respectively, a first residual vector entry being based on the first residual model and one of the first measured results of the respective first subset, and a second residual vector entry being based on the second residual model and one of the second measured results of the respective second subset; computer program code for determining a first residual average and a first residual standard deviation of the first residual vector for each first subset, and a second residual average and a second residual standard deviation of the second residual vector for each second subset, such that each of the multiple tools has a corresponding first residual average, first residual standard deviation, second residual average, and second residual standard deviation; computer program code for, for each of the multiple stages, determining an overall index based on the first residual average, the first residual standard deviation, the second residual average, and the second residual standard deviation for each of the multiple tools in the respective stage; computer program code for identifying at least one of the multiple stages as a key process stage when the at least one of the multiple stages has a corresponding overall index greater than a threshold; computer program code for forecasting a trend of a wafer based on routing of the wafer through some of the multiple stages through the key process stage; and computer program code for dispatching the wafer to one of the multiple tools in at least one stage of the multiple stages subsequent to the key process stage in the processing line based on the trend.