In a GxP environment with bespoke pharmaceutical equipment you are spending anywhere from 1-4000 collective labour hours and anywhere from 50k-250k for a control system upgrade, URS/TRS/SDS, Code risk assessment and review, and Qualification. To give you an idea, on a therapeutic manufacturing plant you're looking at a handful of two inch binders for the end to end system.

You are also (and more importantly) taking your resources off BAU or revenue generating improvement work for this project. You have a validated and qualified system, and even if you are spending $10-20k for a $500 like for like IPC or control card, the cost benefits of another 5 years is worth it.

If your equipment is a medical device, such as a diagnostic microscope, add another few binders of paperwork and regulator sign off. There's a reason the equipment is so expensive

If you get into the food industry, or general manufacturing the barriers to upgrade are much less. For your machine shop running floppy disks, it's a case of the external cost would approach the cost of a new machine, and the existing machine is fine.

As a maintenance professional this is the sort of risk management we conduct on an ongoing basis.