The goal of the study was to improve software process models by applying the 80/20 rule in the Waterfall model of software engineering. By focusing on the most important activities that contribute to 80% of productivity, the software development effort can be reduced and the overall performance of the software process can be increased. The key finding was that by identifying and prioritizing these crucial activities, software project managers can make the software process more efficient and effective, leading to better outcomes in the software industry.