Defensible and Effective Model Based Engineering (MBE) requires capable tools for optimization and simulation to verify that the current system design can meet mission performance, availability and affordability requirements. Legacy Army tools have failed to meet those needs and a new generation of capabilities are now available to allow program managers to continuously update input variables and assess the system’s Operational Availability (Ao) Key Performance Parameter (KPP) and Lifecycle O&S cost Key System Attribute (KSA).