The biggest share of the German travel market is tour packages. A usual tour package contains the flight to the destination and back, transfers from the airport to the hotel and back, board, and lodging. The market share for individual tours is much smaller than in the United States and other countries. It is common practice to offer tour packages that could not be sold until four weeks before departure as last-minute tours. Usually, a discount is given to the customer for these tour packages. Especially in recent years, the market for last-minute packages has grown by a vast amount, and there are specific properties related to these products:
Property 1: Travel agents struggle with the update problem. As many as 6000 new packages are offered daily by just one of the major German tour providers. Traditionally, tour providers send several dozen sheets of paper to their travel agents every day to inform them about available special offers.
Property 2: The method of informing agents by stacks of papers implies an availability problem. Often, the amount of places that can be booked on a specific offer is highly limited. Hence, when customers decide on one of the offers, there is a high risk that it is no longer available because there is no feedback about offers that have been brought to the market in recent days; that is, it is not clear whether these offers are still available or not.
Property 3: Last-minute offers (as provided by the tour providers) are tour packages. Thus, the customer can accept an offer only as it is; there are no variations to it (except if it is stored as a separate offer). Consequently, there is no negotiation during the sales process.
Property 4: Although there might be a huge number of offers, it is unlikely that the desires of a customer can be fulfilled all at once. Rather, it is often the case that alternative departure dates, neighboring airports, or even other destinations need to be suggested. In contrast to people having planned and prepared their holiday carefully, customers looking for last-minute vacations expect such variations. It seems that electronic commerce would be a good way to sell these travel packages. Some of the tour operators are offering database-driven systems on the web to sell their tour packages.(1) A shortcoming of these applications is that ordinary search requests (usually internally realized with some database query language) are not sufficient enough. Customers usually have a certain idea of what kind of tour they would like to book. They do have a preferred country, departure date, and length of tour. If the customer now specifies the request in detail, then most of the time, a traditional system tells the customer "No hits found!" meaning that no tour package in their database matches the request exactly (no solution situation). The customer then has to widen the request by leaving some of the input fields blank. The result is that the system probably will present the customer with several thousand possible tour packages (1000-solutions situation). These lists are usually not even ranked according to the request of the customer; so, the customer has to look through all the presented offers to find the best-matching tour package. The behavior of these conventional systems does not reflect a sales process at all. A good travel agent would never tell a customer that there is no tour package matching the request and send him/her away. Instead, the travel agent would propose some similar tour packages. Thus, an application was needed that implements a vague matching and ranks the found tour packages according to the customer's request.
The last-minute travel application (figure 1) is only one part of a complete VIRTUAL TRAVEL AGENCY. As an electronic-commerce application, it is fully accessible by the web. The customer usually connects to the last-minute travel application by following a link from the web pages of the VIRTUAL TRAVEL AGENCY. …