It is the "input-output ratio". It refers to the ratio of the total investment of the project to the total industrial added value produced during the operating life cycle. It is applicable to the economic effect evaluation indicators of scientific and technological projects, technological transformation projects and equipment renewal projects.

Expressed by the formula:

R = K/IN = 1/N

Where:

K is the total investment

IN is the sum of the added value of each year during the life of the project

N = IN / K

The larger the N value, the better the economic efficiency of the project.