When I worked in manufacturing we had an ERP system that was awful, and we ended up supplementing it with Excel spreadsheets and an Access database. I briefly started writing my own ERP system to replace the whole system, but I realized something: my ERP system would be hopelessly tied to our process at this company, and wouldn't be usable by the manufacturer down the street, which my buddy worked at, without extensive rewriting. Software of this kind has a tension between being general-purpose and being really good for one specific workflow.
Maybe ERP is one of those things that co-evolves with the company, shaping the company as much as it's shaped by the company.
This I think will be the future. The ERP I made for my company is hopelessly tied to our process, and it saves time and reduces mental overhead for everyone.
It evolves as we do with me making feature updates and bug fixes every few weeks. Of course this is unusual in that I’m a very technical owner, but I feel this is the right way.
As software becomes easier to make custom software will reduce in price as well. Software gives my company an edge and I’ll take every advantage I can get.