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The FY11 Report to Congress on Annual Long-Range Plan for Construction of Naval Vessels (commonly known as the 30-Year Shipbuilding Plan) forecasts that the Navy's Attack Submarine (SSN) force structure will fall below the requirement of 48 SSNs in 2024, and will remain below the requirement throughout at least 2040 (the limit of the current report). Operating the fleet with fewer ships than necessary to meet commitments around the globe makes it imperative to maximize the mission time provided by each platform. Accordingly, the VIRGINIA Class Submarine Program Office (PMS 450) has developed a plan to mitigate this shortfall in force structure by designing reductions in depot-level maintenance, thereby improving operational availability and maximizing mission time. This plan is encompassed in the Program Office's Reduction of Total Ownership Cost (RTOC) goals. However, actions arising from pressure to reduce Total Ownership Cost (TOC) may have the potential to inadvertently limit available platform mission time if the full consequences, including indirect impacts, are not rigorously assessed and analyzed in advance. The VIRGINIA Class Submarine Program faced this challenge explicitly in implementing the RTOC program while simultaneously working through details of a class maintenance plan modification for later submarines that adds a deployment to the operating cycle. Reducing TOC, while making changes to both the maintenance plan and the platform design, requires an integrated analytic capability to assess the impact of potential changes to both cost and delivered mission time. Evaluating the impact of maintenance changes on mission time is complicated by interactions between multiple stakeholders involved in controlling and managing the lifecycle of the submarine—including those responsible for maintenance planning (and the ability of the maintenance facilities to execute the work), operations and training, and modernizations. An approach and analytic framework, which captures “TOC Effectiveness” (defined as Mission Time Delivered divided by Net Cost) is needed to balance divergent program and stakeholder goals. To capture TOC effectiveness, a time-phased dynamic simulation of the lifecycle employment of VIRGINIA Class Submarines (including depot maintenance time) has been developed to determine the likely submarine employment consequences of the plans, policies, and constraints of the stakeholders involved, and to ensure that the lifecycle maintenance plan targets are achieved. The simulation was validated against historical performance of LOS ANGELES Class maintenance execution at public shipyards, explicitly adjusting for known differences in VIRGINIA Class work packages (the first VIRGINIA Class depot maintenance availability did not start until October 2010). Simulation analysis has identified likely results of alternative plans and/or policies and provided insight into where changes can be made across multiple stakeholders to efficiently and effectively achieve program goals for deployments. The simulation is integrated into the VIRGINIA Class RTOC program process to identify specific areas where changes have high leverage to increase mission time, evaluate specific changes proposed by the RTOC effort, and track progress toward achieving mission time goals.

Today's ship acquisition environment demands the delivery of more ship for less money. The VIRGINIA Class Submarine Program faced this challenge explicitly, with its mandate to achieve cost reduction of approximately $400 million per ship by FY 2012 as a necessary condition for increased production. For VIRGINIA Class, accomplishing this objective meant implementing a number of significant cost reducing changes to a mature design and hundreds of construction processes—ensuring that these changes enhanced rather than disrupted the “normal” learning occurring in the serial submarine construction. Managing these changes and their impact on ongoing efforts to achieve good learning from ship to ship (also known as the learning curve) was further complicated by interactions between learning and other factors like changes to production rate, funding profiles, construction schedules, and the workforce. Performance of the VIRGINIA Class Program was dynamically simulated to determine in advance the likely full consequences (including indirect impacts) of cost reduction actions in the context of evolving program conditions. The simulation of VIRGINIA Class Program performance captured individual factors whose improvement together drives the classic learning curve—for example, design maturity, material availability, staff experience, and so on—and was validated against historical program performance. This simulation capability was used to evaluate the full impact of potential changes, individually and in combination, along with sensitivity to a variety of different future scenarios. The analysis provided insights regarding the degree of disruption from different cost reduction changes, synergies between these changes, and interactions with other program conditions. This provided an independent “reality check” on the path taken by the VIRGINIA Class cost reduction effort, guidance regarding key sensitivities and risks to be managed, and data that supported contracting for the next block of ships.

Beginning in 1997, the UK government called on London Underground Limited (LUL) to assess its options for a broad restructuring. LUL commissioned an analysis by PA Consulting Group featuring the development and use of a system dynamics simulation model of the Underground. This article describes major aspects of this work, and how use of the dynamic simulation model has evolved to meet LUL's changing needs. The model provided a common framework for analyzing structural options; simulated performance under different potential structures and identified critical aspects of implementation; helped educate LUL's potential private-sector partners about the Underground; and, most recently, enhanced LUL's evaluation of the private sector bids. Copyright © 2001 John Wiley & Sons, Ltd.

An oil spill cleanup system was developed to operate offshore with minimal requirements for vessel and personnel coordination. This Vessel of Opportunity Skimming System (VOSS) consists of a skimming barrier towed alongside a single vessel with an outrigger. Suction hoses run to pumps on deck, which are powered by a diesel-hydraulic powerpack. Recovered fluid is pumped through an oil-water separator before being directed to storage. The first VOSS units were installed aboard the LOOP Vigilance, a shrimp boat modified for oil spill response by the Louisiana Offshore Oil Port (LOOP). The use of these units in two small offshore spills is described. This field experience helped to identify operational practices for maximum system efficiency in various spill situations. System improvements have been made and areas for further development determined.