This study presents a novel approach to project status prediction in software engineering, based on unobservable states of decisionmaking processes, utilizing Hidden Markov Models (HMMs). By establishing HMM structures and leveraging the Rational Decision Making model (RDM), we encoded underlying project conditions; observed project data from a software engineering organization were utilized to estimate model parameters via the Baum-Welch algorithm. The developed HMMs, four project-specific models, were subsequently tested with empirical data, demonstrating their predictive potential. However, a generalized, aggregated model did not show any sufficient accuracy. Model development and experiments were made in Python. Our approach presents preliminary work and a pathway for understanding and forecasting project dynamics in software development environments.