IRM: Integrated Recoverability Model
Traditional vulnerability analysis uses fault tree analysis (FTA); provides static assessment of best possible end state following damage. Limitations include: doesn't account for initial systems configuration. Unable to assess degraded performance. Can't assess automation versus manual actions. However, the condition after a ship is hit is dynamic.
Simulations need to interact with fire and flooding. Can the crew get from point A to point B? Cascading effects.
In 2002 US Navy sponsored initial development of an IRM to address limitations of existing models and simulations.
IRM determines the ship's mission capability over time by simulating the ship's system, considering the interaction and dependencies of connected equipment, plant configuration and crea ctions over time.
IRM: battle damage, Ship Destruction, Output logs, feeds data into: Deckhouse collapse module, flooding module, fire module.
Ship Description database: SQLite is used. 50+ tables. Describes systems, people, info to start up fire model. Can export to other systems.
Where does Tcl/Tk come in?
Damage zone analysis: determine vulnerable areas; evaluate system metrics; evaluate manpower; reduce uncertainties through statistical modeling.
Tcl/Tk allowed rapid interations of the design of the tools. Navy personnel they worked with loved that.
Fire fighting assumptions: ... crew immediately aware of the situation; (compensate with delays before response starts).
Movies shown created by stepping through simulation, using Img package to capture canvas contents, stitch together using common tools.
Within the IRM software Tcl/Tk applications are used to: