Rather: they can decrease development time.
Rather: they are supported by many software tools, some even in the public domain.
Rather: they are part of it.
Rather: they can equally well be applied to hardware design.
Rather: there are many situations where they are desirable.
Rather: there are various standards supporting them.
Rather: it is recognized that certain aspects of system development are better dealt with in other ways.Quoted from: Jonathon P. Bowen and Michael G. Hinchey, Seven more myths of formal methods, IEEE Software, 12(4):34-41, July 1995.