Assessment and accreditation portfolios tend to include quantitative measures of student performance gauged against a set of learning outcomes that have been identified by an instructor, program, department or institution. By using reports that aggregate and analyze data surrounding student learning in relation to a predefined set of educational outcomes, these types of portfolios provide a rich source of information about the actual results of the teaching and learning process and can therefore help institutions align their institutional practice with their stated institutional mission or goals.
Currently I avoid, as much as I can, LMSs. Instead I kluge together a loose collection of free web applications, (Eduspaces Community blog, PBwiki, Pageflakes, Audacity, a password-protected mark site, and whatever free file-hosting service my current students recommend.) It's a bit more work than using a LMS but I believe this approach, the kluging together of a selection of free web services, is a richer and more productive teaching practice.