1. A computer-implemented method for determining a best alias rule in a semiconductor manufacturing process, the method comprising: obtaining an original rule and candidate alias rules; comparing the original rule to the candidate alias rules; ranking the candidate alias rules according to the comparison; filtering the ranked candidate alias rules; and selecting one rule among the filtered candidate alias rules based on a user's knowledge of the semiconductor manufacturing process, wherein the ranking includes: computing each distance from each candidate alias rule to the original rule; ordering the candidate alias rules in an ascending or descending order of the computed distances; comparing the computed distance of each candidate rule with at least one threshold; removing one or more of the candidate alias rules if the computed distance of the one or more of the candidate alias rules does not satisfy the at least one threshold, wherein the computing includes: calculating a full-alias value of each candidate alias rule, the full-alias value representing a measured degree of a similarity between a candidate alias rule and the original rule; calculating a used-alias value of each candidate alias rule, the used-alias value representing a measured dependency or correlation between a first tool step included in the original rule and a second tool step included in a candidate alias rule; and calculating a target-alias value of each candidate alias rule, the target-alias value representing a measure of a relative difference between a first target mean associated with the original rule and a second target mean associated with a first candidate alias rule, the first target mean including first measurements associated with the original rule, the second target mean including second measurements associated with the first candidate alias rule, the first candidate alias rule being one or more of the candidate alias rules, the first measurements including one or more of speed, power consumption and yield rate of semiconductor products manufactured according to the original rule, the second measurements including one or more of speed, power consumption and yield rate of semiconductor products manufactured according to the first candidate alias rule.