Business needs change. New suppliers with new requirements come in, it has to be adjusted to this accounting change, that personnel change, and Maggie retired, and she knew all the ins and outs of the system better than the current programmers.
That said, if we all went back to keyboard interfaces, green on black screens, and people who used the same software for 10 years and got used to its "quirks", software development would be a lot easier. ;)
Look at the PCs in your bank or an airline, most of them are jut screen scraping a mainframe app that thinks it's talking to a bunch of IBM3270 terminals
What I was saying is that we could build software more quickly if we kept to 3270 interfaces and relied on extensive user training. I know that many moving companies are probably still using software developed for an AS400, and manufacturing still has old software lying around.
We just wouldn't start a new project like that. Software is taking the same amount of time because we keep expecting more from our software.
>mainframe app that thinks it's talking to a bunch of IBM3270 terminals...
...and runs in the simulator.
My bank upgraded from the mainframe though about 5 years ago. This was a painful experiences for everyone, including customers. And now they generate account numbers longer than 6 digits, and customers have to remember longer numbers, appalling.
I can personally* confirm that that is exactly how sites like Orbitz and Cheaptickets worked 4+ years ago. Lots of Java and Linux up front. But deep in the back a bunch of 3270 terminal scrapers to mainframes. But that was then. Hopefully they've upgraded those things by now. Despite the principle of "if it ain't broke, don't fix it" there's also the issue of decreasing compatibility and decreasing availability of folks who know how those things work and can maintain them.
(* If you've bought air tickets or made car rentals on either of those sites, at least back during that era, it's almost guaranteed my code touched your transaction at various points in the search and booking lifecycle.)
That said, if we all went back to keyboard interfaces, green on black screens, and people who used the same software for 10 years and got used to its "quirks", software development would be a lot easier. ;)