Integrated Recoverability Model Keynote

Tcl2008 keynote address by Dan Foos. (Initial notes by MC; please edit/improve/enhance.)

IRM: Integrated Recoverability Model


  • Detection and classification
  • Self Defense: Hard Kill (HK), Soft Kill (SK); countermeasures, electronic attack, tactics


  • Weapons Effects on Ship: Primary damage, Secondary damage, Cascading damage
  • Crew casualities
  • Hull, system and component design


  • Contain Damage
  • Prevent Loss of the ship
  • Treat and evacuate crew casualties
  • Repair and reconfigure eqipment/systems
  • Continue to fight

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?

  • D. Richard Hipp, Clif Flynt, and Sean Woods are among those working on the tcl/tk portions
  • Ship database is created using Tk canvas based data entry tools.
  • Tcl is used as a glue language to knit together stand-alone simulators.
  • A tcl app maintains the ship state during a simulation.
  • A tcl app calculates crew movement, equipment repair, and interactions during a simulation.
  • Tcl/Tk apps are used for post-run analysis.
  • Tcl/Tk used to create custom graphs and diagrams for reports

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.


  • Provide improved analysis capabilities
  • Support rapid design trade-off decisions beyond cost and weight
  • Support improved metrics for survivability
  • Should be used to measure and enhance ship survivability

Within the IRM software Tcl/Tk applications are used to:

  • Knit together stand-alone simulators
  • Maintains the ship state during a simulation
  • Calculate crew movement, equipment repair and interactions during a simulation
  • Conduct post run analsys
  • Create ship database