Stratifying Systems Via Relative Projective Modules

In this paper we point out that the "Process of standardization", given in Dlab and Ringel (1992), and also the "Comparison method" given in Platzeck and Reiten (2001) can be generalized. To do so, live introduce the concept of relative projective stratifying system and prove a result from which the Theorem 2 in Dlab and Ringel (1992) and Proposition 2.1 in Ringel (1991) follows.