A Simulation Model for Military Aircraft Maintenance and Availability

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A Simulation Model for Military Aircraft
Maintenance and Availability

• Tuomas Raivio, Eemeli Kuumola,Ville A. Mattila,
• Kai Virtanen and Raimo P. Hämäläinen
• Systems Analysis Laboratory
• Helsinki University of Technology

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Outline

• Aim of the study
• Aircraft fleet operations
• Simulation model description
• Model validation, results
• Concluding remarks

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Aim of The Study

• Development of a simulation model for a fleet of
  military aircraft
• Here Bae Hawk Mk51 jet trainer
• Normal peacetime use
• Training patrol flights
• Maintenance
• Failure repair
• Performance measures
• Flight and maintenance policy planning
• Determine the accuracy needed in modelling such a
  system

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Operations of The Fleet

• Complex and dynamic logistic system
• Need to understand functioning of the system as a
  whole

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Maintenance and Repair Organization

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The Simulation Model

• Discrete event simulation approach
• The model describes
• The structure and interaction of the maintenance,
  repair and flight processes
• The maintenance capacity in terms of manpower
• Outputs from the model
• Performance measures (e.g. aircraft availability)
• Availability operatingAC / total AC

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Structure of The Model
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Modeling Assumptions

• Three airbases are aggregated into one airbase
• Model describes average operations
• Maintenance operations are modeled in terms of
  maintenance duration and manpower capacity
• Other maintenance resources are assumed to be
  available all the time

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Input Parameters

• Most significant parameters
• Maintenance durations and maintenance intervals
• Failure repair durations and failure intensities
• Maintenance manpower capacities
• Flight mission durations and intensities
• Reference data collected by the FAF from several
  airbases
• Point estimates and variances, or distributions
  estimated
• Scaling to represent the aggregated base

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Implementation

• ARENA simulation software
• SIMAN based simulation engine
• Easy-to-use graphical interface
• Animation for easy demonstrating
• Possibility to create standalone models for
  nonexpert users

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Screenshot from Arena
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Model Validation

• Model structure is evaluated together with the
  maintenance and logistics staff of the FAF
• Quantitative validation
• Aircraft availability
• Simulated average availability slightly larger
  than reference value
• Maintenance throughput times
• Simulated throughput times are 0-30 shorter than
  reference values

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Simulated Daily Availability
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Example Analysis
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Conclusions

• ARENA based implementation
• Easy what-if scenarios
• Illustrative animation capabilities
• Stand-alone applications for e.g. maintenance
  staff training
• Rapid estimates for relative effect on system
  performance in case of
• Major changes in maintenance capacity, flight
  intensity etc.
• Aircraft modification programs
• Future modelling efforts
• Insight to sensitive parts of the system
• Easily upgradable platform