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#Virginia class submarine berthing software

Learning from Experience, Volume 2: Lessons from the U.S. The Virginia Class Submarine Program: A Case Study. Defense Acquisitions: Assessment of Selected Weapon Programs Report. The identification of a list of feasible architecture evaluation metrics was an added benefit of the effort. In summary, the work on the Virginia class submarine prompted a change in the traditional architectural approach used in the sonar community to design submarine sonar and validated the cost savings in both research and development (R&D) and in component costs when transitioning from proprietary interfaces to industry standard interfaces. These best practices included stringent design trades to keep costs under control, careful consideration of technical maturity of components, and the importance of program stability. These are discussed by Schank (2011), GAO (2008), and General Dynamics (2002). The Virginia class submarine acquisition exhibited other best practices.

Online testing (e.g., whether the system is operational during external testing and the ease of access to external test points).

Whether the system state at time of system failure can be recreated.

Number of LRUs covered by built-in tests (BIT) (BIT coverage).

Accessibility (e.g., space restrictions, special tool requirements, special skill requirements).

Maintainability (e.g., expected mean time to repair (MTTR), maximum fault group size, whether the system can be operational during maintenance).

Critical points of fragility (e.g., system loading comprised of percent of processor, memory, and network loading).

Reliability, maintainability, and testability.

Common guidelines for implementing human-machine interface (HMI).

Common guidelines for implementing diagnostics and performance monitor/fault location (PM/FL).

Number of proprietary and unique operating systems.

Ratio of the number of form factors to the number of line replaceable units (LRUs).

Number of business domains that apply/use the standard (e.g., aerospace, medical, and telecommunications).

Number of vendors for products based on standards.

Ratio of the number of interface standards to the number of interfaces.

Level to which the architecture includes implicit interfaces.

Number of different networking protocols.

Number of unique interfaces per system element.

Abstraction (i.e., the level to which the system architecture provides an option for information hiding).

Level to which common specifications are identified.

Level to which throughput requirements span across interfaces.

Level to which functional requirements are fragmented across multiple processing elements and interfaces.

Functional modularity (e.g., ease of adding new functionality or upgrading existing functionality).

Physical modularity (e.g., ease of system element or operating system upgrade).

Estimated maintenance training time (e.g., initial and refresh from previous system).

Estimated operational training time (e.g., initial and refresh from previous system).

Percentage of operational functions which are automated.Percentage of HW and SW technology known.Percentage of vendors and subcontractors known.Physical familiarity (with other systems).

#Virginia class submarine berthing software

Software (SW) commonality (e.g., the number of unique SW packages implemented, languages, compilers, average SW instantiations, and unique standards implemented).Hardware (HW) commonality (e.g., the number of unique line replaceable units, fasteners, cables, and unique standards implemented).Physical commonality (within the system).The Virginia class submarine sonar system architecture has improved modularity, commonality, standardization, and reliability, maintainability and testability (RMT) over historical sonar systems.īased on the new architectural approach architectural approach and the success of the transition, system architecture experts developed an initial set of architecture evaluation metrics: The lead ship of the program, Virginia, reduced the number of historically procured parts for nuclear submarines by 60% with the use of standardization. The Virginia class submarine system design represented a transition to COTS-based parts and initiated a global change in architectural approaches adopted by the sonar community. However, in the mid-1990s, the United States government transitioned to the use of commercially developed products - or commercial off the shelf (COTS) products - as a cost-saving measure to reduce the escalating costs associated with proprietary-based research and development. Prior to the Virginia class submarine, sonar systems were comprised of proprietary components and interfaces. 2 Architectural Approach: Standardization.