MR-02 · Heavy Maintenance (C/D Check) Planning

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Process Flow Diagram (BPMN)

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L4 Process Steps

Step	Step Name	Role / Swim Lane	System	Input	Output	KPI	Dec?	Exc?
Phase 1 1.1	Extract aircraft maintenance due-date forecast	Maintenance Planning Engineer	CAMP (Continuous Airworthiness Monitoring Program)	Aircraft flight hours, cycles, and calendar days from ACARS/flight ops feeds	Due-date forecast report showing C/D check windows per tail number	Forecast horizon ≥12 months; 100% of fleet tails covered	N	N
1.2	Review AD/SB compliance status per tail	Airworthiness Engineer	CAMP	FAA Airworthiness Directives feed, manufacturer Service Bulletins, CAMP compliance tracker	AD/SB compliance gap list with mandated incorporation deadlines	Zero open mandatory ADs at check induction; SB review complete ≥90 days pre-induction	N	Y
1.3	Determine check type: C-check vs D-check	Maintenance Planning Manager	AMOS by Swiss AviationSoftware	Aircraft age, total flight cycles, last heavy check date, AD requirements	Confirmed check type decision (C1/C2/C3 or D-check) entered in AMOS	Check type confirmed ≥9 months prior to induction date	Y	N
Phase 2 2.1	Generate MPD baseline work package in AMOS	Maintenance Planning Engineer	AMOS by Swiss AviationSoftware	Approved check type, aircraft MPD (Boeing Maintenance Planning Document), AMOS task library	Baseline work package with task cards, intervals, and estimated manhours	Baseline work package issued ≥8 months prior to induction; manhour estimate accuracy ±10%	N	N
2.2	Incorporate deferred defects and open MEL items	Technical Records Analyst	AMOS by Swiss AviationSoftware	Deferred defect register, MEL (Minimum Equipment List) open items from line maintenance logs	Updated work package with deferred items assigned to check package	100% of Category A/B MEL items resolved at or before heavy check; deferred defect backlog cleared	N	Y
2.3	Add Engineering Orders and requested modifications	Engineering Standards Engineer	AMOS by Swiss AviationSoftware	Engineering Orders (EOs), STC modifications, cabin reconfiguration requests from fleet planning	Supplemental work scope with EOs and mods task-carded in AMOS	All approved EOs incorporated ≥6 months pre-induction; no scope additions within 60 days of induction	N	Y
2.4	Validate work scope against C-check threshold	Maintenance Planning Manager	AMOS by Swiss AviationSoftware	Completed work scope package, manhour estimates, EO add-ons	Scope classification confirmed: C-check or escalated to D-check in AMOS	Scope re-classification decisions completed within 5 business days of scope freeze; re-scope rate <5% of planned checks	Y	N
Phase 3 3.1	Estimate total manhours and skill requirements	Maintenance Planning Engineer	AMOS by Swiss AviationSoftware	Approved work scope package with task cards	Manhour demand plan broken down by trade (structures, avionics, engines, interiors)	Manhour forecast accuracy ±15% vs actuals; plan issued ≥6 months pre-induction	N	N
3.2	Identify and order long-lead rotable parts	Supply Chain Planner	SAP S/4HANA Finance (MM / Procurement)	AMOS work package BOM, CAMP part cross-reference, current inventory positions	Long-lead parts list with order quantities, lead times, and due-in dates	100% of long-lead parts (lead time >90 days) on order ≥6 months pre-induction; stockout rate at induction <2%	N	Y
3.3	Raise material requisitions for consumables and hardware	Supply Chain Planner	SAP Ariba	AMOS-generated materials list, approved vendor catalogue in SAP Ariba	Purchase requisitions raised and approved in SAP Ariba; delivery schedule confirmed	All consumable PRs raised ≥90 days pre-induction; on-time delivery rate ≥95%	N	Y
3.4	Confirm critical parts availability at MRO site	Maintenance Planning Manager	AMOS by Swiss AviationSoftware	SAP Ariba purchase orders, MRO facility inventory feed, Boeing Toolbox part status	Parts readiness confirmation report; open shortages escalated	Parts readiness confirmation completed 30 days pre-induction; critical shortage count = 0 at induction	Y	N
Phase 4 4.1	Issue RFQ to approved heavy MRO facilities	Procurement Manager – MRO	SAP Ariba	Approved work scope package, manhour estimates, parts supply plan, desired induction window	RFQ document issued to ≥3 qualified MRO vendors via SAP Ariba sourcing event	RFQ issued ≥9 months pre-induction; minimum 3 qualified vendor responses received	N	N
4.2	Evaluate vendor bids on TAT, cost, and capability	Procurement Manager – MRO	SAP Ariba	Vendor bids, MRO capability audit records, historical TAT performance data	Bid evaluation scorecard with vendor ranking; recommendation memo	Evaluation complete within 15 business days of bid close; cost variance between lowest and selected bid <8%	N	N
4.3	Confirm bid meets TAT and unit cost targets	VP Maintenance & Engineering	SAP Ariba	Bid evaluation scorecard, fleet plan TAT requirements, approved MRO budget	Approved vendor selection or instruction to re-issue RFQ / negotiate	Contract TAT ≤21 days for C-check, ≤45 days for D-check; unit cost within ±5% of approved budget	Y	N
4.4	Award contract and raise PO in SAP	Procurement Manager – MRO	SAP Ariba / SAP S/4HANA Finance (FI/CO)	Approved vendor selection, agreed contract terms, budget approval	Signed MRO contract, purchase order raised in SAP S/4HANA, cost centre committed	PO raised within 5 business days of approval; contract signed ≥6 months pre-induction	N	Y
Phase 5 5.1	Compile aircraft technical documentation package	Technical Records Analyst	AMOS by Swiss AviationSoftware	Aircraft log books, CAMP airworthiness records, work scope package, AD/SB status report	Complete pre-induction documentation pack transmitted to MRO facility	Documentation package delivered to MRO ≥14 days before induction; zero missing mandatory documents at induction gate	N	Y
5.2	Coordinate ferry flight and fleet schedule impact	Network Operations Planner	Amadeus SkyWORKS	Confirmed MRO induction date, aircraft tail assignment, fleet plan from SkyWORKS	Ferry flight plan, substitute aircraft allocation, schedule change notification to OCC	Ferry flight confirmed ≥21 days pre-induction; schedule impact to revenue flying <2 affected rotations	N	Y
5.3	Complete pre-induction readiness checklist	Maintenance Planning Manager	AMOS by Swiss AviationSoftware	Documentation pack status, parts delivery confirmations, ferry flight plan, MRO slot confirmation	Signed pre-induction checklist; go/no-go decision for induction	Checklist signed-off 7 days pre-induction; no-go rate due to planning gaps <3%	Y	N

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Process Attributes

Identification

Process IDMR-02

L1 DomainMaintenance, Repair & Overhaul

L2 ProcessHeavy Maintenance

L3 NameHeavy Maintenance (C/D Check) Planning

L4 Steps18 across 5 phases

Decision Gates5 (all with iteration loops)

Exceptions8 documented

Swim Lanes (Roles)

Maintenance Planning Engineer

Airworthiness Engineer

Maintenance Planning Manager

Technical Records Analyst

Engineering Standards Engineer

Supply Chain Planner

Procurement Manager – MRO

VP Maintenance & Engineering

Network Operations Planner

Systems & Tools

CAMP (Continuous Airworthiness Monitoring Program)CAMPAMOS by Swiss AviationSoftwareSAP S/4HANA Finance (MM / Procurement)SAP AribaSAP Ariba / SAP S/4HANA Finance (FI/CO)Amadeus SkyWORKS

Key Performance Indicators

Extract aircraft maintenance due-date forecastForecast horizon ≥12 months; 100% of fleet tails covered

Review AD/SB compliance status per tailZero open mandatory ADs at check induction; SB review complete ≥90 days pre-induction

Determine check type: C-check vs D-checkCheck type confirmed ≥9 months prior to induction date

Generate MPD baseline work package in AMOSBaseline work package issued ≥8 months prior to induction; manhour estimate accuracy ±10%

Incorporate deferred defects and open MEL items100% of Category A/B MEL items resolved at or before heavy check; deferred defect backlog cleared

Add Engineering Orders and requested modificationsAll approved EOs incorporated ≥6 months pre-induction; no scope additions within 60 days of induction

Validate work scope against C-check thresholdScope re-classification decisions completed within 5 business days of scope freeze; re-scope rate <5% of planned checks

Estimate total manhours and skill requirementsManhour forecast accuracy ±15% vs actuals; plan issued ≥6 months pre-induction

Airline-Specific Risks & Pain Points

CAMP data sync lag from ACARS can understate actual FH/FC by 1-2 cycles, risking check due-date miscalculation

Rapid-fire AD releases (e.g. Boeing MAX ADs post-737 MAX groundings) can invalidate a pre-built work scope days before induction

Legacy aircraft approaching D-check thresholds (typically 8-12 years) may be upgraded mid-plan; late D-check designation inflates TAT and cost >40%

MPD revision cycles from Boeing (quarterly) can introduce new tasks after baseline is locked, requiring rework of the work package

MEL items deferred beyond permissible intervals can trigger unplanned component removals, extending TAT by 3-5 days

Cabin modification requests (seat layout changes, IFE upgrades) arriving late can increase ground time by 5-10 days and require renegotiation of MRO slot

Inputs / Outputs

Primary InputAircraft flight hours, cycles, and calendar days from ACARS/flight ops feeds

Primary OutputSigned pre-induction checklist; go/no-go decision for induction

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