1. A computer-implemented workforce analysis method for solving L1-based clustering problem of multinomial distributions of workforce data, the method comprising the steps of: acquiring workforce allocation data; arranging the workforce allocation data in sets of fraction data with respect to the L1 distances; clustering the sets of fraction data t corresponding set of cluster centers, or L1 distances for each set; minimizing the sets of fraction data based on the cluster centers or L1 distances; and outputting analysis results of the clustering problem; wherein the steps are executed by a processor.