Consider the following two investment alternatives:Suppose that your firm needs either machine for only 2 years. The net proceeds from the sale of machine B are estimated to be $200. What should be the required net proceeds from the sale of machine A so that both machines could be considered economically indifferent at an interest rate of 10%?

A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. 
An 'information system' means a discrete set of information resources organized for the collection, processing, maintenance, use, sharing, dissemination, or disposition of information.

Engineering economics, previously known as engineering economy, is a subset of economics concerned with the use and "...application of economic principles" in the analysis of engineering decisions.