scope:

This guideline deals with all dynamic methods of calculation of economic efficiency, which are characterized by the following features:

• use of different change rates for various costs or types of payment
• explicit allowance for costs and payments which occur at different periods, i. e. doing away with average cost rates per period, in contrast to the static method
• taking account of the uncertainty or risk of future costs or payments

Where the use of such characteristic data is omitted, this results in principle in the static methods as a special case within the dynamic methods.

A distinction must be particularly be made between

• new and expansion investments and
• replacement investments, conversion investments and cost saving investments

when applying the methods for calculation of economic efficiency.

The equations and examples were of course meant for application in the area of engineering which consumes heat but can also be transferred to other technical applications.