The Delphi technique has been used for meeting several challenges, including [1, 3, 4]:
Delphi has been applied in a large number of domains  including business, economics, finance, health care, sales and strategic planning.
Real-life cases where Welphi has been used for:
1. Linstone, H.A. and M. Turoff, The Delphi method: Techniques and applications. 2002, Reading: Addison-Wesley.
2. Keeney, S., F. Hasson, and H. McKenna, The Delphi technique in nursing and health research. 2011, Chichester: Wiley Blackwell.
3. Gupta, U.G. and R.E. Clarke, Theory and applications of the Delphi technique: A bibliography (1975–1994). Technological forecasting and social change, 1996. 53(2): 185-211.
4. Warner, L.A., Using the Delphi Technique to Achieve Consensus: A Tool for Guiding Extension Programs. 2014, Agricultural Education and Communication Department, UF/IFAS Extension.