I don’t want to sound flippant or rude, so please accept my apologies if it comes across that way.
The first thing is to ask yourself why do you want to migrate away from it. If you have reasons that are more than just a personal preference or ambition then you need to quantify those in terms of what’s to be gained by moving and what’s lost by staying.
After that you need to do the same exercise with what you want to migrate to.
Personally I couldn’t think of a good reason to move away from the AS/400, iSeries of System i5 to another platform – although the business might think otherwise.
Nothing to improve is answer…. just 100% agree with it…
There are great reasons to keep the code and migrate to another OS like Linux and run the apps on X series blades that are virtualized. You can’t use VMWare on i OS. That means you can’t get dynamic allocation and you can ‘t get on board fast cheap High Availablility. HA costs a fortune for i os and you need to buy a lot of expensive hardware. You could just run your RPG or COBOL applications on LInux on cheap X Series blades using the same DB. if you migrated the code to Linux or AIX. The DB2 fees are crazy expensive and so is the cost of i OS.