Relationships between Offers, OfferParts, Products and Fares

The entities offer, offerpart, product and fare represent different concepts.

An offer spans the trip consisting of segments. An offerpart spans a segment or - in the case of through fares - multiple segments. An offerpart references zero or two products. Mostly, the relationship is one-to-one (zero in case of included seat reservation, whereas two products are only referenced in some rare TGV-TER scenarios).

A fare is not necessarily bound to segments but reflects the tariff worlds. A fare often starts or ends at country borders where no train station exist. This border points are thus called virtual border points which can be modelled by ConnectionPoints. Fares are combined following a fare combination model to an offer.

See Constructing Products from Fares to understand how fares are combined to products, offerparts and offers.