Abstract: A two-step procedure for pattern assignment. The initial assignment is based on a heuristic criteria that like lines should be separated from one another to the greatest degree possible, but with a constraint that two "like" conductors should not be located in adjacent locations in the pattern if at all possible. The initial assignment pattern is then optimized by an iterative procedure to reduce Delta-I noise to a minimum. Assignments in a small sub-matrix (for example a 3x3-matrix) of the entire pattern are iteratively changed and the Delta-I noise for each iterative is determined to establish a pattern for the sub-matrix with the minimum Delta-I noise. Adjacent sub-matrices are examined in the same manner with this important criteria. Each sub-matrix after the first, overlaps at least one row or column of a previous optimized sub-matrix, and the pin assignments in the overlap portion remain frozen when optimizing the adjacent sub-matrix.