where Wi is the normalized weighting for the ith criterion; ri is the ranking score for the ith criterion; and n is the number of decision criteria. The scoring analysis was applied using two scales of importance ( Table 4a and b); in the first, the importance of each criterion is scored from 1 to 5; and the second one allocate the successive scores from 1 to 8 for each criterion (where 1 is the most important). The results of scoring analysis with these two scales represented the first and second alternatives.