ABSTRACT
On some occasions the acquisition of one of several systems, all performing basically the same
function, is definitely necessary regardless of the suitability of the investment in another type
of business. In these cases the net present worth is the method preferred, especially in military,
government, or social systems where almost equal benefits are obtained from different systems
under consideration; therefore, the benefit is a non-differential factor. When comparison of 10!
alternatives with different lives or different initial investments is considered, the uniform
