This research was initiated a result of a proposition described by Cleland and King in 1983. They proposed that the management of a portfolio-of-projects could be achieveda s a by-product of using a MIS containing project-management data. The hypothesis in this research takes their proposition further. It contends that the application of Pareto-based heuristics in the management of a portfolio-of-projects can improve on their approach. The research has been undertaken in Hong Kong. However, a review of the literature defines Hong Kong as a 'city-state' construction industry that is shown to be similar to national industries elsewhere. On this basis, the research establishes its validity for the general-case. Two qualitative surveys have been completed to identify the current methods used by Hong Kong contractors and by Hong Kong consultants for the management of their portfolios-of-projects. These elements of the research did not find evidence that in general, firms used a MIS that transformed project-level performance data to manage portfolios-of-projects. In this respect, there was no notable evidence of the adoption of the project-to-portfolio MIS data-pipeline described by Cleland and King. These surveys did not provide evidence that the commonly used 'individual review' or 'spreadsheet analysis' of multi-project data for portfolio management included prioritisation to identify projects of most significance to the outcome of the portfolio. Empirical data from the public works element of the Hong Kong construction industry is used in simulations of portfolio management to test the hypothesis along with a longitudinal grounded case study of the implementation of a portfolio/project MIS within the Hong Kong Government (HKG SAR). This case study provided practical experimentation through the quantitative measurement of 'before' and 'after' effects of a change to project-based multi-project management techniques that fitted the Cleland and King model. A qualitative survey has been completed to assess the degree of success and User satisfaction with this practical experimentation. The results of these elements of the research are taken to mean that the hypothesis is supported in principle. The final element of the research uses the empirical data to investigate the effectiveness of basing success for the portfolio-of-projects largely on the outcome of the important projects within the portfolio. Monte Carlo techniques are used to simulate an achievable excellent performance for the projects deemed as significant within the portfolio whilst the outcome for the other projects is unchanged. The simulated improved performance for the significant projects is based upon a derived probability-distribution-function (PDF) that represents the top twenty percent of project achievement for the portfolio-of-projects. The simulated outcome provides evidence in support of the hypothesis. With the exception of one of the ten cases tested, the theoretical application of excellent outcomes for the significant twenty percent of the number of projects using Monte Carlo techniques results in a worthwhile improved outcome for the portfolio as a whole. In the exceptional case, the actual result was already in agreement with the theoretical proposition. All ten cases, thereby showed the hypothesis to be true within the specifics and constraints of this research.