New Complexity
From here, Ferneyhough became closely associated with the so-called New Complexity school of composition (indeed, he is often referred to as the "Father of New Complexity"), characterized by its extension of the modernist tendency towards formalization (particularly as in integral serialism). Ferneyhough's actual compositional approach, however, rejects serialism and other "generative" methods of composing; he prefers instead to use systems only to create material and formal constraints, while their realisation appears to be more spontaneous.