Individuals and corporations are permanently facing critical choices in selecting the best options to optimize their own limited resources or sorting out how to maximize the profitability of their investments.

The Economic and Financial environment will participate their decisions for the choice of the most profitable investment, through such parameters like financial markets outlook, external funds availability, interest rates, inflation, taxes policies…but a more subjective perception of TIME will keep a key role in our global appreciation.

The methodology based on discounted cash-flows, as developed in this guide, can be applied to any kind of investment, and uses universal criteria allowing the selection of any form of investment or spending, with and without external financing. It is explaining the central role of TIME in the appreciation of the VALUE. This guide is also providing elements on methods to include risk and uncertain future in profitability analysis and investments selection.

Last, an introduction is made to public investments selection methodologies.

Its aim is to assist engineers, bankers, deciders… in an investment evaluation in using common concepts and a common language, to support the decision of individual consumers in their everyday life, and to allow non-financial officers and students to better understand the criteria used by banks and financial institutions. Detailed formulas have been minimized and focus brought on the meaning methodologies of selection, with practical cases. A dedicated companion website is allowing a connection to a suite of spreadsheets detailing the simulation of study cases, through a financial model involving the key parameters. The reader may use it to perform his own simulations, to improve it with the inclusion of other parameters, or to add a risk analysis simulation.