Evaluating planning strategies for prioritizing projects in sustainability improvement programs

Programs to improve the sustainability of building infrastructures often consist of project portfolios that need to be prioritized in an appropriate chronological fashion to maximize the program’s benefits. This is particularly important when a revolving-fund approach is used to leverage savings from the initial projects to pay for later improvements. The success of the revolving-fund approach is dependent on the appropriate prioritization of projects. Competing performance measures and scarce resources make this task of project prioritization during the planning stage a complex and challenging endeavour. The current study examined the impact of different project prioritization strategies for revolving-fund sustainability program performance. A novel modeling approach for sustainability decision-analysis was developed using the system dynamics method, and the model was calibrated using a campus sustainability improvement program at a major university. The model was applied to evaluate the effects of five common project-prioritization strategies on three program-performance measures, across a wide range of initial investment levels. For the university case study, we found that the strategy of prioritizing projects according to decreasing benefit/cost ratio performed best. The research demonstrated that using a system dynamics model can allow sustainability program managers to make better-informed sequencing decisions, leading to a financially and environmentally successful program implementations.