This example is patterned after an example described in Dalal and Mallows (1998). An originating phone (Near Phone) calls a receiving phone (Far Phone). Each phone call goes through an interface of type A or B. Five factors are of interest:
• Market: USA, UK, Canada, France, Mexico
• Near Phone: ISDN, Bus (Business), Coin, Res (Residential)
• Near Interface: A or B
• Far Phone: ISDN, Bus (Business), Coin, Res (Residential)
• Far Interface: A or B
You are interested in which combinations of pairs of these factors are likely to cause failures. However, certain combinations are not possible:
• An ISDN line on either phone (Near or Far) cannot use interface A.
• Business and Residential lines on the originating phone (Near) cannot use interface B.