Problems from Autonomic Logistics: Constraints from a Domain

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Problems from Autonomic LogisticsConstraints
from a Domain

• Gabor Karsai
• ISIS

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Problem set

• Dynamic Maintenance Scheduling
• Optimize schedule to increase sortie generation
• Deferred maintenance actions

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Dynamic Scheduling

• Traditional calendar-based maintenance
• Fixed schedules (based on MTBFs)
• Move towards condition-based maintenance
• Fly as long as it works
• When it is about to break, schedule maintenance

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Dynamic SchedulingDomain objects and relations
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Dynamic SchedulingScheduling problem - Inputs

• Given...
• MT set of maintenance tasks
• M set of mechanics
• T set of tools
• P set of parts

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Dynamic SchedulingScheduling problem -
Constraints

• Under the constraints...
• requiresSkills(mt MT) gt s S
• requiresTools(mt MT) gt t T
• requiresParts(mt MT) gt p P
• hasSkills(m M) gt s S
• requiresTime(mt MT) gt int

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Dynamic SchedulingScheduling problem - Outputs

• Generate schedule SCH as list of tuples
• ( m M, mt MT , start Time, length Time )
• Such that
• a mechanic works on one task at a time
• all tasks are eventually performed

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Dynamic SchedulingRe-scheduling problem

• Inputs
• Same as before MT, M, T, P
• Current schedule SCH
• New maintenance task MT
• Output
• Updated schedule SCH
• Such that...
• Changes are minimal

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Schedule to improve Sortie Generation

• Sortie generation depends on
• Number of aircraft available for missions
• Other resources (fuel, munitions, etc.)
• Goal
• Increase sortie generation rate

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Sortie GenerationDomain objects and relations
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Sortie GenerationThe Task

• Input
• Set of all feasible schedules (given MT,M,T,P)
• Desired number of sorties as function of time
• desiredSorties(tTime) gt int
• Output
• One (or more) schedules that allow the desired
  number of sorties over time

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Deferred Maintenance Actions

• Aircraft Prognostics and Health Management System
  predicts impending failure sometime in the future
• Result maintenance action that can be delayed
• Maintenance schedule is adjusted in coordination
  with operational schedule

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Deferred Maintenance Actions Domain objects and
relations
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Deferred Maintenance Actions The Task

• Input
• Set of all feasible schedules (given MT,M,T,P)
• Operational schedule ltAircraft,Start,Lengthgt
• Predicted failure mode FM (with timeout)
• Output
• One (or more) schedules that satisfy operational
  schedule and will have the MT performed before
  timeout

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The desired solutionAgents and Algorithms

• Architecture necessitates search through multiple
  databases
• Solutions should be generated through a
  negotiation process
• Quick, acceptable solutions are preferred over
  slow, optimal solutions