That's my sort of filing system too ... 10 years ago - before such things were commonplace - I lead a project to move an 18 strong secretarial team to using a document management system.
We had had a high turnover of secretaries and higher than acceptable levels of sickness (company culture was the main reason!) and so frequently we couldn't access complex documents started and stored on a particular home directory - completely inefficient AND we had no concept of avoiding sharing passwords - nightmare!
We created our own inhouse system based on our Lotus Notes server. It was so successful it was fully adopted by a 100 strong technical team as well and was still running when I left 5 years later.
We didn't get as far as scanning all incoming documents to go totally paperless - partly down to volume of incoming and partly because the situation regarding Revenue documents wasn't certain (as an accountancy practice we handled many Revenue documents for our clients).
I was - and still am - extremely proud of the system we created; a cross discipline team working together to scope, develop, roll out, train and troubleshoot the system, buy-in from a larger user base and longevity - project manager's dream
