Three functions, three honest answers
Route profitability is one of the few management reports in an airline that three separate functions produce independently. Network planning builds a contribution view to decide where capacity goes next season. Finance builds a fully allocated view to reconcile to the ledger. Commercial builds a revenue-quality view to manage pricing and sales performance on the route today.
Each model is internally consistent. The trouble begins when the three land on the CEO’s desk in the same month: one shows the route comfortably positive, one shows it marginal, one shows it loss-making. At that point the debate shifts from “what should we do about the route?” to “whose number is right?” — and decisions stall.
The uncomfortable answer is that none of them is wrong. They are answering different questions with different rules, and nobody has written the rules down side by side.
The allocation choices that drive the gap
The largest divergences come from how shared costs and network revenue are pushed down to route level. The choices that matter most:
- Connecting revenue. Does a feeder sector get credited with a share of the long-haul fare it feeds, and on what proration basis — mileage, straight rate proration, or a negotiated network value? Change the basis and thin domestic routes swing from loss to contribution.
- Aircraft ownership cost. Fleet-average lease and depreciation charges flatter routes flown by older, written-down aircraft and penalise routes flying the newest fleet. Tail-specific costing tells a different story.
- Overhead allocation. Head-office, IT, and corporate marketing costs allocated on ASKs, revenue or departures each produce a different ranking of routes at the margin.
- Fuel price. Actual burn at hedged price, actual burn at market price, or planning-assumption price — three legitimate conventions, three different results in a volatile fuel year.
- Cargo and ancillary credit. Belly cargo contribution and ancillary revenue are often credited in one model and held centrally in another.
None of these is a matter of accuracy. They are policy choices, and the disagreement between reports is really an unresolved policy disagreement between functions.
Timing and data: the quieter causes
Beyond allocation policy sit two quieter drivers. The first is timing. Flown revenue settles through revenue accounting weeks after departure; interline and proration adjustments arrive later still. A commercial report built on sales data and a finance report built on flown, settled revenue will disagree for the same month even before any allocation logic applies.
The second is source data. Models drawing from the reservations system, the revenue accounting platform and the general ledger inherit each system’s exclusions and corrections. Where a route-profitability model has been maintained in spreadsheets for years, mappings quietly drift: new fare families land in the wrong bucket, a re-fleeted route keeps its old cost profile, an exchange-rate table stops updating. These defects do not announce themselves; they surface as an unexplained gap between two reports that both claim the same route.
When three route reports disagree, the organisation does not have three views of profitability. It has none — because no decision-maker can rely on any of them.
What the disagreement costs
The direct cost is decision paralysis: routes that should be retimed, re-gauged or exited survive additional seasons because every review meeting collapses into a methodology argument. The subtler cost is behavioural. Once managers learn that route numbers are negotiable, each function optimises to its own report — commercial defends the revenue view, network defends contribution, and finance’s fully allocated view is dismissed as “accounting”. Board and audit committee members, seeing figures that move between packs, lose confidence in management information well beyond the network department.
Building one agreed view
The remedy is not a single model that abolishes the others — contribution and fully allocated views both have legitimate uses. The remedy is a single, governed methodology with declared layers. In practice that means: a written allocation policy owned by finance and signed off by network and commercial; one data pipeline from revenue accounting and the ledger that every layer draws from; a reconciliation, published with the report, from route contribution up to the ledger result; and a change-control log so that when an allocation rule changes, prior periods are restated and the change is visible.
Independent review has a specific role here: testing whether the model does what the policy says, whether mappings are complete, and whether the reconciliation genuinely closes — the assurance that turns a negotiated number back into a trusted one.
Where to start
Take one contested route and have each function walk its number back to source in a single working session. The gaps that emerge — a proration basis here, a stale mapping there — become the first draft of the allocation policy. Most airlines find the disagreement is concentrated in fewer than ten choices; agreeing those, and governing them, is a far smaller task than the years of argument suggest.