1. Barlow, R.E. and Proschan, F. (1981), Statistical Theory of Reliability and Life Testing, To Begin With, Silver Spring, MD.
2. Blanchard, B.S. and Fabrycky, W.J. (1998), Systems Engineering and Analysis, 3rd ed., Prentice‐Hall, Upper Saddle River, NJ.
3. Blanchard, B.S., Verma, D. and Peterson, E.L. (1995), Maintainability: A Key to Effective Serviceability and Maintenance Management, John Wiley & Sons, New York, NY.
4. Carter, A.D.S. (1997), Mechanical Reliability and Design, Macmillian, Basingstoke.
5. Cooper, R.G. (1990), “Stage Gate systems: a new tool for managing new products”, Business Horizons, May‐June, pp. 44‐54.