System Availability Modeling & Analysis Case Studies

1. Systems Availability Modeling & Analysis System Availability Modeling & AnalysisCase Studies Rev 04.30.13

2. System Availability Modeling and Analysis Case Studies • Aircraft A Availability Modeling and Analysis Case Study • Aircraft B Availability Modeling and Analysis Case Study • Blue Frame Aircraft Case Study

3. Aircraft A Availability Modeling and Analysis Case study

4. Operational Concept Support Concept Maintenance Concept The System View • Availability • Sortie Generation Rates • Basing Product • Reliability • Maintainability • Supportability • Testability • Organization • Requirements • Schedule Maintenance • Unscheduled Maintenance • Spares • Technical Publications • Training • Support Equipment

5. Aircraft Availability Model Logic InitiateScenario Fly MissionProfile Yes Trouble Shoot @2-Digit WUC Level No Yes No Service andTurnaround Aircraft No ReadyAircraftAvailable? SubstituteAvailable? SpareAvailable? Repair OnAircraft? In-FlightGripe? Yes Defect? Repair andReturn to ReadyPool Yes No Yes Perform RepairMTL/EMT/MM No Replace Unitand Check Out Yes Remove Item No Repair Item Wait for Spare

24. Aircraft B Availability Modeling and AnalysisCase Study

25. Operational Concept Support Concept Maintenance Concept The System View • Availability • Sortie Generation Rates • Basing Product • Reliability • Maintainability • Supportability • Testability • Organization • Requirements • Schedule Maintenance • Unscheduled Maintenance • Spares • Technical Publications • Training • Support Equipment

26. 67% 15 14 14 12 12 MaintenanceEvents, % Landing Gear FlightControls Propulsion Airframe Avionics Aircraft Systems Maintenance Events Drivers

27. Availability/Readiness (A/R) Model Example Analysis Results

28. Availability/Readiness (A/R) Model Example Analysis Results

29. Availability/Readiness (A/R) Model Example Analysis Results

30. Availability/Readiness (A/R) Model Example Analysis Results

31. Availability/Readiness (A/R) Model Example Analysis Results

32. UnclassifiedAvailability/Readiness (A/R) Model Example Analysis Results

33. Availability/Readiness (A/R) Model Example Analysis Results

34. Availability/Readiness (A/R) Model Example Analysis Results

35. Availability/Readiness (A/R) Model Example Analysis Results

36. Blue Flame Aircraft Case Study

37. Blue Flame Availability Analysis • Previous availability & support system analysis applications (heritage) • Review of Blue Flame Requirements and system/subsystem characteristics • Determination of radar component of Blue Flame availability • Development of Blue Flame radar availability model • Calculation of Blue Flame radar baseline availability estimates

38. Blue Flame Analysis Working Definitions Operational Availability (Ao)- the degree to which an item (the radar set) is in an operable and committable state at the start of a mission when the mission is called for at a random time. • System Reliability Design Characteristics • Mean-Time-Between-Failure (MTBF)-a reliability function which assumes that operation occurs after early failure (infant mortality) and prior to wear-out, I.e., a constant failure rate exists. • Mean-Time-Between-Maintenance-Actions (MTBMA)-a reliability function which accounts for all causes of maintenance activity, whether a failure occurred or not. • System Maintainability Design Characteristics • Mean-Time-To-Repair (MTTR)-a maintenance function, can include corrective maintenance time (CMT) and preventive maintenance time (PMT) • Support System Design Characteristics • Mean-Logistics-Down-Time (MLDT)-a maintenance related logistics function which involves spares provisioning and logistics delay time (LDT) and administrative delay time (ADT)

39. Blue Flame Operational Availability • Inherent Availability (Ai) Ai = • Achieved Availability (Aa) Aa= • Operational Availability (Ao) MTBF MTBF + MTTR(CMT) MTBF MTBF + MTTR MTBF Ao = MTBF + MTTR + MLDT

40. Blue Flame Fleet Requirements • Fleet Requirements • Operational Availability -- 95% • Sortie Rate --12/PAA/Mo (Peacetime) • Mission Reliability --93% (High Mission) --96% (Low Mission) • Fleet Operational Data • 3.5 flying hrs/high mission --50% of missions • 1.5 flying hrs/low mission --50% of missions • 500 aircraft -- one radar set per aircraft • 10 bases -- 50 aircraft per base • 1.5 to 1 ratio of operating hours to flying hours • Radar set has 80% duty cycle relative to aircraft operating hours • Average of 30 flying hours per aircraft per month • 20 year field use period for each radar system

41. Blue Flame Radar Support Characteristics • Maintenance/Logistics Concept • Organizational --Remove/Replace LRUs on aircraft (10 sites) • Intermediate -- Remove/Replace SRUs at shop (10 sites) • Depot -- Repair SRUs (1CONUS site) • Sparing Concept --Intermediate (LRU & SRU) --Depot (SRU & Piece Parts only) • Built-in Test Capability --Fault isolation to faulty LRU @90% --Fault isolation to faulty SRU @90% --Fault detection @ 2% • Support Equipment -Organizational -- None -Intermediate -- Simple PSGE -Depot --ATE • All LRUs and SRUs are repairable

42. Blue Flame R&M Requirements • Aircraft MTBM 4.0 hrs. Aircraft MMH/FH (unscheduled) 3.0 hrs. Aircraft MMH/FH (scheduled) 0.5 hrs. • Radar MTBM 20.0 hrs. Radar MMH/FH 0.5 hrs. Radar Failure Rate Allocation Antenna/Receiver LRU 16,667 failures/10x6 hrs Transmitter LRU 20,000 failures/10x6 hrs Processor LRU 10,000 failures/10x6 hrs Displays/Controls LRU 2,500 failures/10x6 hrs Power Supply LRU 883 failures/10x6 hrs • Radar MTTRs & Scheduled Maintenance Organizational level MTTR 0.5 hrs Intermediate level MTTR 2.5 hrs Depot level MTTR 6.0 hrs XMTR Magnetron replacement: Every 1000 flying hrs, 1 person,4.0 hrs.

43. Miscellaneous Blue Flame Characteristics • Spares turnaround time (TAT) • Intermediate level --75 days • Depot level -- 45 days • Constant failure rate assumed • Re-test OK(RTOK) rate • Intermediate level -- 20% • Depot level -- 8% • Learning curve on maintenance -- 90% • One set PGSE per base • Depot ATE availability -- 80% • Ave. administrative delay time -- 0.75 hrs./repair • Ave. logistics delay time -- 6.6 hrs./repair 90% probability of spare in 2.0 hrs. 10% probability of no spare in 48 hrs.

44. Blue Flame Aircraft system Elements WBS Level 0 –Blue Flame Aircraft WBS Level 1-Major Systems • Airframe • Flight Controls • Navigation • Propulsion • Radar WBS Level 2-Subsystems (Radar) • Antenna/Receiver • Transmitter • Processor • Display/Controls • Power Supply

45. Blue Flame Tradeoff Analyses • Design Tradeoffs Baseline -- single transmitter Alternate -- redundant transmitters (2) – operating redundancy • Support Tradeoffs Baseline -- 90% spares assurance Alternate -- 80% spares assurance The big question before the house is: Where do we start?

46. Blue Flame Aircraft Radar Availability – Case Study Review the ‘Blue Flame Case Study’ excel spreadsheet and check/verify the availability numbers corresponding to a single transmitter on the next page and show the results of your analysis.

47. Radar Trade Result Summary Radar Availability at stated Spares Level Design Option 90% Spares 80% Spares Single Transmitter 65% 55%