a simulation model for aircraft maintenance in an uncertain operational environment
DESCRIPTION
A Simulation Model for Aircraft Maintenance in an Uncertain Operational Environment. Ville Mattila, Kai Virtanen and Tuomas Raivio Systems Analysis Laboratory Helsinki University of Technology. Objective. - PowerPoint PPT PresentationTRANSCRIPT
1
S ystemsAnalysis LaboratoryHelsinki University of Technology
A Simulation Model for Aircraft Maintenance in an Uncertain Operational Environment
Ville Mattila, Kai Virtanen and Tuomas Raivio
Systems Analysis Laboratory
Helsinki University of Technology
2
S ystemsAnalysis LaboratoryHelsinki University of Technology
Objective
• Modeling and simulation of flight and maintenance
operations of the aircraft fleet of the Finnish Air Force
(FiAF)
• Prediction of supportability requirements and fleet
performance – Effect of operating conditions
– Effect of operating policies and supposed system improvements
• Special interest in conflict operations– Uncertainty involved in the operational environment
3
S ystemsAnalysis LaboratoryHelsinki University of Technology
Development
2000 2004
Early considerations in FiAF, static failure models
Initiative for simulation of aircraft maintenance, joint project between FiAF andSystems analysis laboratory
Discrete-event simulation as approach, Arena software as tool
Simulation model of one airbase
Model with multiple airbases, normal and conflict operations
A simulation tool for FiAF
Simulation of helicopter maintenance
Introduction in FiAF
Scheduling of aircraft maintenance
4
S ystemsAnalysis LaboratoryHelsinki University of Technology
Discrete-event simulation
• Widely applied in analyzing logistic systems
– Conceptually simple approach
– Intuitive consideration of uncertainty
– Allows the inclusion of highly
complex processes and interactions
in a model
– Possibilities for visualization
– Powerful software tools for model
construction and analysis, flowchart modeling
ENTER_M A_HUO LTO O N_O HJAUS Dec ide 63T r u e
F a ls e
Dec ide 64
A I K A _ M A _ 9 _ H U O L L O S T A > ( M A _ 9 _ H U O L T O V A L I - M A _ 9 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 9 _ V A L I N T A = = 1A I K A _ M A _ 8 _ H U O L L O S T A > ( M A _ 8 _ H U O L T O V A L I - M A _ 8 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 8 _ V A L I N T A = = 1A I K A _ M A _ 7 _ H U O L L O S T A > ( M A _ 7 _ H U O L T O V A L I - M A _ 7 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 7 _ V A L I N T A = = 1A I K A _ M A _ 6 _ H U O L L O S T A > ( M A _ 6 _ H U O L T O V A L I - M A _ 6 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 6 _ V A L I N T A = = 1A I K A _ M A _ 5 _ H U O L L O S T A > ( M A _ 5 _ H U O L T O V A L I - M A _ 5 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 5 _ V A L I N T A = = 1A I K A _ M A _ 4 _ H U O L L O S T A > ( M A _ 4 _ H U O L T O V A L I - M A _ 4 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 4 _ V A L I N T A = = 1A I K A _ M A _ 3 _ H U O L L O S T A > ( M A _ 3 _ H U O L T O V A L I - M A _ 3 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 3 _ V A L I N T A = = 1A I K A _ M A _ 2 _ H U O L L O S T A > ( M A _ 2 _ H U O L T O V A L I - M A _ 2 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 2 _ V A L I N T A = = 1A I K A _ M A _ 1 _ H U O L L O S T A > ( M A _ 1 _ H U O L T O V A L I - M A _ 1 _ H U O L T O V A L I _ T O L ) * 6 0 & & M A 1 _ V A L I N T A = = 1
E ls e
T r u e
F a ls e
Dec ide 65 Ass ign 106
T r u e
F a ls e
Dec ide 66 Ass ign 107
T r u e
F a ls e
Dec ide 67 Ass ign 108
T r u e
F a ls e
Dec ide 68 Ass ign 109
T r u e
F a ls e
Dec ide 69 Ass ign 110
T r u e
F a ls e
Dec ide 70 Ass ign 111
Ass ign 112
Leave 19
T r u e
F a ls e
Dec ide 96Ass ign 146
T r u e
F a ls e
Dec ide 97 Ass ign 147
T r u e
F a ls e
Dec ide 98 Ass ign 148
Dec ide 182
L A I V U E T U N N U S = = 1L A I V U E T U N N U S = = 2
E ls e
Leave 35
Leave 36
Jakaum a
Jakaum a
Jakaum a
Jakaum a
Jakaum a
Jakaum a
Jakaum a
Jakaum a
Jakaum a
5 1 4 4
0
3
0
2
0
6
0
1 1
0
1 9
0
6 6
0
0
0
0
0
0
0
5
S ystemsAnalysis LaboratoryHelsinki University of Technology
Aircraft availability
Maintenance•resources•operating policies•environment
Flight activities•modes of flying•intensity•selection of aircraft
Battle damages•threat scenarios•tactics
Reliability•Deterioration•Preventive measures
6
S ystemsAnalysis LaboratoryHelsinki University of Technology
Conflict operations
• Limited knowledge on how the presence of the
enemy affects the fleet’s operations
– Unpredictable flight pattern
– Battle damage rates
– Changed maintenance requirements
– Decentralization of airbases
– Material supply
– Assaults on airbases
7
S ystemsAnalysis LaboratoryHelsinki University of Technology
The simulation model
Need for periodic Need for periodic maintenance?maintenance?
Damages?Damages?
Failures?Failures?
MissionMission
Central depot
SquadronsSquadrons
AirbasesMaintenancelevels
Fuel and materialsFuel and materials supply supply
Personnel
Aircraft availability
8
S ystemsAnalysis LaboratoryHelsinki University of Technology
Construction and validation of the model
• Based on incomplete information
• Emphasis on expert knowledge– Conversations with FiAF representatives
– Presentations to maintenance professionals
– Available data on normal operations, exercises and contingency
plans
• Affects the way the model can be used– Definition of input data
– Interpretation of results
– Sensitivity analyses
9
S ystemsAnalysis LaboratoryHelsinki University of Technology
Utilization of the model
• Implemented with Arena -software
• Appears as a stand-alone tool to the user – Customized user interface and simulation reports
• Simulation analyses for maintenance designers– Allocation of maintenance personnel, spare parts and equipment
– Comparison of flight and maintenance policies
– Effect of reliability improvements...
• Applicable for training of maintenance personnel– Demonstrates the significance of maintenance and support
logistics to performance of the fleet
10
S ystemsAnalysis LaboratoryHelsinki University of Technology
Example analysis
• Change of maintenance policy during a dynamically evolving conflict– Periodic maintenance is suspended to release aircraft to flight
activities
• At what time should this occur?
• A scenario with 4 phases1 Increased flight intensity
2 Further increase in flight intensity, decentralization of airbases
3 Aerial battles
4 Decreased flight intensity due to losses
11
S ystemsAnalysis LaboratoryHelsinki University of Technology
Example analysis: results
0
0.2
0.4
0.6
0.8
1
0 50 100 150 200 250
Time (days)
Av
aila
bilit
y
In 1st phase In 2nd phase
In 3rd phase Not employedEmployment of new policy
1. 2. 3. 4.
12
S ystemsAnalysis LaboratoryHelsinki University of Technology
Conclusions
• A simulation model for the aircraft fleet of FiAF
• Quantitative assessment of supportability
requirements and fleet performance– Diverse operating policies and conditions
• A tool for maintenance designers and training of
maintenance personnel– Introduced to Air Force units