MR-03 · Engine Shop Maintenance Management

📊

Process Flow Diagram (BPMN)

📋

L4 Process Steps

Step	Step Name	Role / Swim Lane	System	Input	Output	KPI	Dec?	Exc?
Phase 1 1.1	Receive engine from aircraft and log induction	Engine Shop Receiving Inspector	AMOS by Swiss AviationSoftware	Engine removal notification from line maintenance or heavy check	Engine induction record with serial number, TSN, CSN, and removal reason	Induction record created within 4 hours of engine receipt	N	N
1.2	Perform incoming borescope inspection of engine	Engine Borescope Inspector (Part 145)	AMOS by Swiss AviationSoftware	Induction record, engine removal reason, last borescope findings	Borescope inspection report with blade condition, FOD, and erosion findings	Borescope inspection completed within 24 hours of induction; findings logged in AMOS within 2 hours of inspection	N	Y
1.3	Determine shop visit type and open work order	Engine Shop Planning Engineer	AMOS by Swiss AviationSoftware	Borescope report, engine removal reason, performance trend data	Shop visit classification (Performance Restoration, HSI, or On-Condition) and AMOS work order	Work order opened and shop visit type confirmed within 8 hours of induction	Y	N
Phase 2 2.1	Disassemble engine modules per CMM procedures	Engine Overhaul Mechanic (Part 145)	AMOS by Swiss AviationSoftware	AMOS work order, OEM Component Maintenance Manual (CMM), tooling list	Disassembled engine modules staged for inspection; AMOS task cards signed off	Module teardown completed within published CMM man-hour estimate ±10%	N	N
2.2	Inspect HPC, HPT, LPT, and fan modules	Engine Inspector / NDT Level II	AMOS by Swiss AviationSoftware	Disassembled modules, OEM Airworthiness Limitations (AWL), AD compliance matrix	Module inspection findings report; life-limited part (LLP) status updated in AMOS	100% LLP cycle verification against AMOS life-limit records; inspection findings report issued within 48 hours of module receipt	N	Y
2.3	Identify AD/SB compliance gaps and raise EOs	Engine Planning Engineer	AMOS by Swiss AviationSoftware	Module inspection report, FAA AD database, OEM service bulletin index	Engineering Orders (EOs) raised in AMOS for each open AD/SB; updated work scope	Zero open mandatory ADs at engine release; all applicable SBs evaluated within 24 hours of findings report	Y	N
Phase 3 3.1	Classify parts as BER, serviceable, or repairable	Engine Shop Planner	AMOS by Swiss AviationSoftware	Teardown findings report, OEM serviceability limits, repair cost benchmarks	Parts disposition list with BER (Beyond Economic Repair), serviceable, and repair-route tags in AMOS	Parts disposition completed within 48 hours of teardown; BER rate benchmarked at ≤15% of total parts count	N	Y
3.2	Check rotable parts availability in pool	Engine Materials Controller	Boeing Toolbox / CAMP	Parts disposition list, rotable pool inventory records	Availability confirmation or shortage list for critical engine parts	Rotable pool fill rate ≥85% for engine shop demand; critical part shortage identified within 4 hours of disposition	Y	N
3.3	Raise purchase orders for parts shortages	Engine Materials Controller	SAP Ariba	Shortage list from CAMP, approved vendor list (AVL), engine TAT deadline	SAP Ariba purchase orders for parts; expected delivery dates entered in AMOS parts tracking	PO raised within 8 hours of shortage confirmation; expedited orders for AOG parts placed within 2 hours	N	Y
Phase 4 4.1	Repair and overhaul modules per CMM	Engine Overhaul Mechanic (Part 145)	AMOS by Swiss AviationSoftware	Module inspection report, EOs, CMM repair procedures, serviceable replacement parts	Repaired modules with AMOS task cards signed; NDT records attached	Repair man-hours within ±15% of AMOS work-order estimate; first-pass quality rate ≥92%	N	Y
4.2	Apply approved modifications and service bulletins	Engine Planning Engineer	AMOS by Swiss AviationSoftware	Open SB list from Step 2.3, OEM modification kits, Engineering Orders	Modification compliance records in AMOS; updated engine configuration baseline	100% mandatory SB incorporation confirmed before assembly; optional SB cost/benefit review completed within 4 hours	N	N
4.3	Reassemble engine and verify build standard	Engine Overhaul Mechanic (Part 145)	AMOS by Swiss AviationSoftware	Repaired and serviceable modules, torque specifications, build standard document	Fully assembled engine; AMOS build record with component serial numbers and final configuration	Assembly completed within 48 hours of all parts arrival; dimensional check non-conformance rate ≤5%	Y	Y
Phase 5 5.1	Install engine on test cell and configure parameters	Test Cell Engineer	Trax (MRO Software)	Assembled engine, test cell acceptance test procedure (ATP), engine spec sheet	Engine installed on test cell; baseline parameters configured in Trax test run record	Test cell installation completed within 4 hours; test cell utilisation rate ≥80%	N	N
5.2	Run engine acceptance test per ECTM limits	Test Cell Engineer	Trax (MRO Software)	OEM Acceptance Test Procedure (ATP), Engine Condition Trend Monitoring (ECTM) limits, test cell instrumentation data	Test run data report: EGT margin, fuel flow, vibration, oil consumption vs. OEM limits	EGT margin ≥25°C at end-of-test; vibration ≤0.5 in/sec; oil consumption ≤0.5 qt/hr	Y	Y
Phase 6 6.1	Complete FAA 8130-3 / EASA Form 1 release docs	Authorised Release Certificate Signatory (Part 145)	AMOS by Swiss AviationSoftware	Test cell certification, AMOS work order completion data, AD/SB compliance records	FAA 8130-3 or EASA Form 1 Authorised Release Certificate; closed AMOS work order	Release documentation completed within 8 hours of test cell sign-off; zero documentation deficiencies at FAA/EASA audit	N	Y
6.2	Update engine life history and rotable records	Engine Records Administrator	Boeing Toolbox / CAMP	Closed AMOS work order, LLP cycle updates, modification compliance records	Updated engine life history in CAMP; rotable pool inventory record updated with new TSO/CSO	Engine history updated within 4 hours of work order closure; LLP discrepancy rate ≤0.1% at next audit	N	N
6.3	Obtain QA airworthiness release approval	Quality Assurance Manager (Part 145)	AMOS by Swiss AviationSoftware	Complete AMOS work order, release certificate, CAMP history update confirmation	QA-signed airworthiness release; engine cleared for return to rotable pool or direct fitment	QA release granted within 4 hours of documentation package submission; zero engines released with open corrective actions	Y	N
6.4	Return engine to rotable pool and notify planning	Engine Shop Manager	AMOS by Swiss AviationSoftware	QA airworthiness release, engine storage requirements, fleet demand forecast	Engine tagged serviceable in AMOS rotable pool; network planning team notified of availability	Engine available in rotable pool within 2 hours of QA release; total shop visit TAT vs. target reported monthly	N	N

📋

Process Attributes

Identification

Process IDMR-03

L1 DomainMaintenance, Repair & Overhaul

L2 ProcessEngine & Component Shop

L3 NameEngine Shop Maintenance Management

L4 Steps18 across 6 phases

Decision Gates6 (all with iteration loops)

Exceptions8 documented

Swim Lanes (Roles)

Engine Shop Receiving Inspector

Engine Borescope Inspector (Part 145)

Engine Shop Planning Engineer

Engine Overhaul Mechanic (Part 145)

Engine Inspector / NDT Level II

Engine Planning Engineer

Engine Shop Planner

Engine Materials Controller

Test Cell Engineer

Authorised Release Certificate Signatory (Part 145)

Engine Records Administrator

Quality Assurance Manager (Part 145)

Engine Shop Manager

Systems & Tools

AMOS by Swiss AviationSoftwareBoeing Toolbox / CAMPSAP AribaTrax (MRO Software)

Key Performance Indicators

Receive engine from aircraft and log inductionInduction record created within 4 hours of engine receipt

Perform incoming borescope inspection of engineBorescope inspection completed within 24 hours of induction; findings logged in AMOS within 2 hours of inspection

Determine shop visit type and open work orderWork order opened and shop visit type confirmed within 8 hours of induction

Disassemble engine modules per CMM proceduresModule teardown completed within published CMM man-hour estimate ±10%

Inspect HPC, HPT, LPT, and fan modules100% LLP cycle verification against AMOS life-limit records; inspection findings report issued within 48 hours of module receipt

Identify AD/SB compliance gaps and raise EOsZero open mandatory ADs at engine release; all applicable SBs evaluated within 24 hours of findings report

Classify parts as BER, serviceable, or repairableParts disposition completed within 48 hours of teardown; BER rate benchmarked at ≤15% of total parts count

Check rotable parts availability in poolRotable pool fill rate ≥85% for engine shop demand; critical part shortage identified within 4 hours of disposition

Airline-Specific Risks & Pain Points

Incomplete removal documentation from line stations delays accurate TSN/CSN capture, risking life-limit tracking errors in AMOS

FOD damage discovered at induction not captured in aircraft logbook leads to retroactive safety investigations under FAR Part 43.9 and delays work scope confirmation

Performance trend data from on-wing ACARS monitoring (SITA ACARS) may not sync to AMOS automatically, forcing manual EGT margin entry and introducing transcription errors

OEM CMM revision cycle (Boeing/CFM/GE) lags regulatory changes; AMOS document revision alerts can be suppressed by users, risking use of superseded procedures

LLP cycle counter discrepancies between AMOS and Boeing Toolbox / CAMP cause certification holds; reconciliation requires manual cross-check, averaging 6–8 hours per engine

FAA AD compliance is checked against AMOS AD library which requires manual updates; a delayed AD import (>30 days) creates regulatory exposure under FAR Part 91.409 and Part 43 Appendix D

Inputs / Outputs

Primary InputEngine removal notification from line maintenance or heavy check

Primary OutputEngine tagged serviceable in AMOS rotable pool; network planning team notified of availability

←PreviousMR-02 · Heavy Maintenance (C/D Check) Planning NextMR-04 · Component & Parts Management→