Systems Developmental Dependency Analysis for Scheduling Decision Support: The Lunar Gateway Case Study

Project Managers face many difficulties when scheduling the development and production of multiple, largely independent systems required for a new capability, especially when there are multiple stakeholders, uncertainties in the expected development time, and developmental dependencies among the systems. The Systems Developmental Dependency Analysis methodology provides a systemic approach to address these challenges by offering decision support for such a ‘System-of-Systems’. The method, based on a parametric piece-wise linear model of dependencies between elements in the developmental domain, propagates the interactions between systems to estimate delays in the development of individual systems and to evaluate the impact of such delays on the expected schedule of completion for the establishment of the whole desired capability. The schedule can be automatically re-generated based on new system information, changed dependencies, and/or modified risk levels. As demonstrated in this paper using a complex space mission case, the method enhances decision-support by identifying criticalities, computing possible delay absorption strategies, and comparing different development strategies in terms of robustness to delays.