Gallery: An inside look at Boeing's production plant in Everett

The Boeing production plant is one of the largest building in the world. The map demonstrates where each widebody aircraft will be built. The transition process from the 777 to  777X is expected to take around three years.

A wing-section and part of the fuselage of a Boeing 777. A 777 will be built in around 14 weeks. A Boeing 747-8 takes about 6.5 months and is composed of 6 million parts.

A Norwegian 787-9 nears completion. Around 30,000 Boeing workers are in Everett, working in three shifts.

LOT Polish Airlines' second Boeing 787-9.

The biggest  777 customer is Dubai-based Emirates Airline. Another 777 will join the airline shortly. Boeing said it has 1,926 orders for the "legacy" 777 and the 777X in total.

A view of the Boeing 777-300ER production line. The aircraft to the right is dedicated to Qatar Airways. The first one on the left will be built for United Airlines, and behind that is a Korean Air 777.

A closer look at the manufacturing section. In the back of the hall, the first preparations for the 777 to 777X transformation process is underway.

Work on a Qatar Airways 777-300ER.

Airline logos demonstrate Boeing's worldwide 787 customers.

A sticker on the fuselage shows the owner and operator of this 787-9.

SWISS took delivery of its 10th 777-300ER on March 13, which is Boeing´s 1,545th 777 built since 1994.

The SWISS 777 flew to Zurich March 13; the LOT 787 (behind) will fly to Warsaw March 22.

Boeing's delivery flight line at Everett is dominated by 787s.