Writing in the company's 2013 annual report, published on Tuesday, Norwegian chief executive Bjørn Kjos said that demand for seats on the new long-haul routes had outstripped his expectations.
"The demand for a low-cost alternative to Southeast Asia and North America is clearly illustrated by load factors, which averaged 90 per cent in 2013 – about 5 percentage points higher than we expected," he wrote.
However, he conceded that the launch of the services had not been without problems.
"During the first months of operation, delays were inevitable and passengers flew more often on replacement aircraft than on the Dreamliner. This was not the product we wanted to offer to our passengers," he wrote.
He also said that the high start-up costs of the operation and its initially small scale meant that "it did not make a positive contribution to unit cost during the first year".
However, he said that with the Dreamliner aircraft now perfuming "beautifully", he had decided to nearly double his next Dreamliner order from eight to 14, the last six of which are a stretch version of the 787-8, called the 787-9.
The upbeat annual report comes as the company's Norway and Denmark based cabin crews are threatening to go on strike as early as next week if a government-led mediation over their pensions and the company's staff reorganisation fails.
In his commentary to the annual report, Kjos argued that Norwegian had no choice but to recruit more staff from low-cost countries if it is to compete.
"Though Scandinavians are statistically among the most frequent travellers in the world, they are in limited supply," he wrote.
"To maintain a competitive edge outside Scandinavia, expansion into new markets must be on a level playing field with incumbent airlines. Recruitment for new bases takes place locally to offer competitive and favourable local terms of employment."