Development effort estimation in free/open source software from activity in version control systems

Abstract Effort estimation models are a fundamental tool in software management, and used as forecast for resources, constraints costs associated to development. For Free/Open Source Software (FOSS) projects, effort is especially complex: professional developers work alongside occasional, volunteer developers, so the overall (in person-months) becomes non-trivial determine. The objective of this it develop simple model FOSS based on historic data developers’ effort. fed with direct developer feedback ensure its accuracy. After extracting personal development profiles several thousands from 6 large we asked them fill questionnaire determine if they should be considered full-time project that in. Their was fine-tune value an threshold, above which can full-time. With help over 1,000 questionnaires received, were able determine, every our sample, threshold commits separates non-full-time developers. We finally offer guidelines apply projects use version control system.