As a general rule in my experience, a re-write will take at least as long as writing the current software. There's a reason that much of our modern banking infr

As a general rule in my experience, a re-write will take at least as long as writing the current software. There's a reason that much of our modern banking infrastructure still lives in COBOL. But that's not a bad thing. It makes a ton of sense. The cost/benefit of a rewrite should be done beforehand and this should be taken into consideration. You'd be surprised at how rarely that happens. It's a false and incorrect assumption that re-writes are cheaper or faster (you are basically re-learning the entire specification of an application). But re-writes also offer a ton of opportunity and benefits and if those are important to your business, then proceed with a re-write.