English to German Bus/Financial Accounting business plan/earn-out payment

In einem Vertrag über die Übertragung von Gesellschaftsanteilen geht es um die Berechnung der Bemessungsgrundlage der Earn-out-Zahlung.

EBITDA
+ Adjustment due to leasing payments
- Adjustment due to net sales of assets
- Adjustment due to the payment made by the Sellers to the Company based on the statutory claims the Company has against the Sellers
+ Adjustment due to capitalisation of overhaulage costs
= Normalised EBITDA
+ Adjustment due to targeted efficiency gains
= Determination base for the Earn-Out Payment

Kann mir jemand sagen, was in diesem Zusammenhang overhaulage costs sind? Es geht um Busunternehmen.

TIA
Birgit