Layer lengths, torsion theories and the finitistic dimension
  Let $\Lambda$ be an artinian ring. Generalizing the Loewy length, we propose the layer length associated with a torsion theory, which is a new measure for finitely generated $\Lambda$-modules. 
Fran\c{c}ois Huard, Marcelo Lanzilotta, Octavio Mendoza
math.RT