Martin S. Feather Steven L. Cornford Kenneth A. Hicks James D. Kiper Tim Menzies A Broad, Quantitative Model for Making Early Requirements Decisions. 49-56 2008 25 IEEE Software 2 http://doi.ieeecomputersociety.org/10.1109/MS.2008.29 db/journals/software/software25.html#FeatherCHKM08