Without further constraints, the only constraints for weights of the input factors and
output factors are that the weights have to be positive. In reality, investors would have different
preference about the weights of factors. Some would think the revenue is at least important as net
income, and some other would think the earnings per share are not as much important as revenue.
These preferences are arbitrary personal assumption, and the result of efficiency would change as
different preferences implement in the data envelopment analysis model. The team first testified
the model without any weights restrictions, and then the team implemented certain constraints of
weights of input/output factors to show the change of the efficiency score by the newlyimplemented
constraints.