E.g. something like:
pkg_staleness = (1 * missed_patch + 5 * missed_minor + 10 * missed_major) * (month_diff(installed_release_date, latest_release_date)/2)^2 proj_staleness = sum(pkg.staleness * pkg.weight for pkg in all_packages)
https://libyear.com/
E.g. something like: