The decision-making process is then intended to achieve and maintain the most valuable option during the lifecycle of the infrastructure service, from its inception to its termination. The introduction of a process for guiding the decisions provides a rational for public intervention for the presence of a market failure. It reduces the discretion of the decision makers not based on technical support, it helps understanding and managing the commitments of the governments and the risk it assumes or transfer, it helps to monitor the quality of the service provided and finally react to maintain that value.
The decision making process must be based on budgetary assumptions that limits the same array of available options. Value is therefore achieved as the best option within those limits. The verification of affordability ex-ante enhances the judgment of value deriving from the decision making process. The use of PPP for bypassing budgetary limits jeopardizes the concept of "best option" and consequently reduces the allocative efficiency as outcome.