Full-featured implementation of the de facto industry standard COCOMO 81 (detailed model) software project effort and schedule estimation algorithms, with extensions that also project cost based on development organization labor grade/pay structure. Calculations are based on estimated program Taille, adjusted for development environment characteristics (complexity, reliability, throughput/memory constraints, etc.). Detailed model supports functional decomposition of program to components that can be more accurately estimated. Attribute factors are applied at all levels of the program structure, allowing best characterization for various differences across the project. SCEP also includes estimates for the reuse of existing modules with modifications.