A superposition technique for multiple-row film-cooling heat-transfer augmentation and effectiveness is investigated. The technique is developed for use with 2-D correlations of film-cooling properties such as film cooling effectiveness and heat transfer coefficients. The method proposed is for implementations with Iterative Conjugate Heat-Transfer using a Reduced Order Film Model (ICHT-ROFM). The superposition technique is used in conjunction with 2-D correlations developed in a previous study for single row of holes to obtain the heat transfer augmentation and film-cooling effectiveness for two staggered rows for dustpan shaped holes. The results are compared to data for multiple-row film-cooling. The results for effectiveness were within 15% of empirical data. The results obtained from using the current technique are compared to spanwise-averaged superposition techniques, which had errors nearing 50%, and it was found to be more accurate.