Abstract
Summary
In fact investment prepared one of the important subjects in the national economy so in the economical project, that because future of the economic unit depends upon the success of the investment.
This search comes in two sections, the first one details the meanings of investment, the aims of investment and the principle factors which effects on the evaluation of investment decision such as profits, inflation rate, markets, finance, time, costs, and the risks the study of these elements very important before taking the investment decision .
Then the second section deals with the study of differentiation methods among investment alternatives and decision making. The investment decisions can be divided to three ranks that is: short term investments, long term investments and strategic investments.
There are many models to differentiate among the alternatives, these models are: rate of investment revenue model, current value model, profiting model, internal revenue model and regaining period model.
We know that each models has merits and defects in addition that the models not consider the conditions of uncertainty in the future. Then the unit may choose that model which suit with its nature and its financial conditions, and these selection achieves the most reality and optimal investment alternative.