Since last years Case Base Reasoning (CBR) field has been growing, and Case Base Maintenance (CBM) is getting more important. Recent research has focused on case-base maintenance, addressing such issues as maintaining consistency, preserving competence, and controlling case-base grow. A set of dimensions for case-base maintenance proposed by Leake and Wilson, provides a framework for understanding and expanding CBM research. Taking this contribution into account, the aims of our work is to do a framework where the basics concepts of CBM are explained, and even more, as second objective we do a brief resume of some relevant contributions made by the scientific CBR community. Starting where Wilson and Leake research work ends.