Quite often, whilst a business has evolved, the administration processes haven’t. Maybe customer details were added to Excel at first, then an accountancy package was brought in which needed the same customer details to be added. Another program was added to handle (as an example) training courses which needed the same details added.
Now you have three systems all recording the same information.
What happens when a customer changes address? You simply log into your software (or open Excel) and change it. But has it been updated across all systems? These are all weaknesses which have the potential of disrupting your business.
What if the address wasn’t updated in the invoicing system? The customer isn’t receiving invoices any more, so they can’t pay them. And you need them paid.
Now you have to trawl through the entire process and find out why they aren’t getting the invoices, all the while taking precious time away from your staff who need to handle their day-to-day workload as well as find what went wrong.