SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Outline Aim of the study Aircraft fleet operations Simulation model description Model validation, results Concluding remarks

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Operations of The Fleet Complex and dynamic logistic system Need to understand functioning of the system as a whole

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Maintenance and Repair Organization

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Structure of The Model

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Screenshot from Arena

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Simulated Daily Availability

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY Example Analysis

SYSTEMS ANALYSIS LABORATORY HELSINKI UNIVERSITY OF TECHNOLOGY 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