Metric coset schemes revisited

An Abelian scheme corresponds to a special instance of what is usually name d a Schur-ring. After the needed results have been quoted on additive codes in Abelian schemes and their duals, coset configurations, coset schemes, m etric schemes and distance regular graphs, partition designs and completely regular codes, we give alternative proofs of some of those results. In thi s way we obtain a construction of metric Abelian schemes and an algorithm t o compute their intersection matrices.