(01 Jun 2018, 8:34 am)8222 wrote In my opinion there are a number of factors to consider.

1 - They need to compete against the A321LR. The 757 is perfect for this; but the current 757s are becoming old. The last one rolled off in 2004 - the technology and the engines are not the most efficient (but definitely some of the most powerful!). 
2 - Boeing have the 737 MAX10 as a competitor to the A321LR. This will somewhat replace the 757 long haul missions - but it is important to note that they say it is not a direct replacement of any of the 737 family. 

I think it would take a lot of effort and money to reopen the production line; as well as a lot of capital investment to update the design. It's easier to do when a model is already in production - such as the A32X Neo series. I think it will want to invest more capital into its 787 and 737 lines, as well as the proven 777 line - especially having just gained approval from the FAA for folding wingtips.

Obviously, this is just my opinion - but it would seem they have made their minds up on this one.

I think it should be essential for boeing to get a newer version of the 757 quickly. Although the A321LR looking like a good replacement and the 737MAX10 looking like a likely replacement, you have got to remember that neither of these aircrafts were designed to cross the pond. The 737 and 787 are for different leagues and are really nothing compared to a 757. Short turnaround times like the 737 but able to cross the pond well like a 787(just). They can keep the same design as far as I can see it. All it would need is new engines.