In this paper, a model and tool is proposed to assist universities and other mission-based organisations to ascertain systematically the optimal portfolio of projects, in any year, meeting the organisations risk tolerances and available funds. The model and tool presented build on previous work on university operations and decision support systems with an added robust process element to the task of reviewing projects that form part of a budget. In addition, the model and tool enable review of risk and return and assists universities and other organisations to determine the optimal mix of projects within a portfolio that provides the greatest financial return and the greatest contribution to the organisations mission. While the paper utilises key academic concepts, it has been created for practical use either inside or outside the budget cycle to assist decision-makers at universities and mission-based organisations. The aim has been to present in a manner to appeal to those with broad finance and accounting skills and to those with a more theoretical understanding of statistics.