I didn't know about business central, a quick Google search tells me it's an ERP. There are alternatives, but migrating an ERP is definitely more problematic than changing document storage and the applications you use to read and write documents. But if it's an ERP, I wouldn't say an electronic sheet like Excel would be an alternative. Or am I missing something?
At enterprise scale migrating to SAP is a 2-3 year project. Most of which is planning, discovery, business analysis and process modeling.