The design aims to make the plane nimble and able to fly long distances without refuelling.
Howard Wheeldon, a transport analyst with BGC Partners, told the BBC World Service that it was a revolutionary project which would reshape aviation.
"This is an aircraft that changes the whole basis of flying, because of the equipment onboard," he said.
"In terms of the cost of operation this is an 80% composite material aircraft, with 35 tonnes of carbon-fibre reinforced plastic, so it is a light aircraft - which means it burns less fuel."
Its arch-rival, Airbus, also has a lightweight craft in development. Its A350 plane will also be made primarily from carbon-composite materials.
Airbus is also targeting a different market with its giant A380, a craft that can carry far larger numbers of passengers although it is limited to flying to those airports that are equipped for the double-decker aircraft.
Battle for the skies
The 787 was first unveiled in July 2007 and is Boeing's first all-new jet since 1995.
The newness of the Dreamliner design has meant a steep learning curve for Boeing and that, and the fact that the company ventured into wide-ranging outsourcing for the first time, has led to a raft of problems.
Early delays to the 787 project were caused by shortages of parts and the difficulties of bringing together fuselage and wing structures from Japan, Italy and elsewhere in the US.
Mr Wheeldon said: "There is a huge test programme - because everything is new. Essentially, it has to be proven, and proven again."
Exactly how much profit Boeing can expect to make from the plane is uncertain.
Analysts say the company has invested more than $10bn in the project, and will have to give some sort of compensation to customers for late planes.
How late the planes are, and how they will perform, will not be known until all the flight tests are completed.
Boeing is not the only plane-maker hit by snags though.
Earlier this month, Airbus's A400M military transport plane finally took to the skies in Spain for its first test flight after a series of delays.
Boeing has said it hopes to deliver the first plane by the end of 2010 to Japan's All Nippon Airlines.
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