Two Stage Optimization Models of the NCSRPE of Programs from the Perspective of Work Daisong Hu, Jingchun Feng, Wenjing Zhao, Yuwei Zhai and Song Xue E3S Web Conf., 251 (2021) 01013 Published online: 15 April 2021 DOI: 10.1051/e3sconf/202125101013