Even in terms of play value it mostly seems to be a trade-off — 60104 loses the vending machine, cafe, baggage x-ray scanner, and a few seats on the plane but gains a baggage conveyor, a restroom, a refueling tank for the plane, an additional minifigure, and more seats in the waiting area. It's pretty nice to see the value of a LEGO air terminal remain fairly stable even though the price has not increased.
Since the 1950s, the Lego Group has released thousands of sets with a variety of themes, including space, robots, pirates, trains, Vikings, castle, dinosaurs, undersea exploration, and wild west. Some of the classic themes that continue to the present day include Lego City (a line of sets depicting city life introduced in 1973) and Lego Technic (a line aimed at emulating complex machinery, introduced in 1977).
Billund Airport had its beginning in 1961 when the son of the founder of the Lego Group, Godtfred Kirk Christiansen, established a private 800-meter long runway and hangar north of his factory in Billund. With Christiansen as a key driver, more of the neighbouring municipalities were included in the group of owners, and it was planned that the airport should be expanded to a regular public airport.
Primary concept and development work takes place at the Billund headquarters, where the company employs approximately 120 designers. The company also has smaller design offices in the UK, Spain, Germany, and Japan which are tasked with developing products aimed specifically at these markets. The average development period for a new product is around twelve months, split into three stages. The first stage is to identify market trends and developments, including contact by the designers directly with the market; some are stationed in toy shops close to holidays, while others interview children. The second stage is the design and development of the product based upon the results of the first stage. As of September 2008 the design teams use 3D modelling software to generate CAD drawings from initial design sketches. The designs are then prototyped using an in-house stereolithography machine. These prototypes are presented to the entire project team for comment and for testing by parents and children during the "validation" process. Designs may then be altered in accordance with the results from the focus groups. Virtual models of completed Lego products are built concurrently with the writing of the user instructions. Completed CAD models are also used in the wider organisation, for marketing and packaging.