Not Just Acces
Way back last century, the toolroom in the factory where I worked had a god-awful scheduling system and a very enthusiastic tooling engineer, who brought in a copy of Superbase and built his own system. It worked quite well for them and kept entirely under our radar.
We (DP) found out about it 55 weeks after it went live, and about 30 weeks after the engineer went on long-term sick. He had, of course, omitted a full date specification and the previous year's jobs were popping back up again. Could we please, fix it for them, please, please?
Of course, we couldn't, at least not quickly.
Part of the reason that it took a couple of weeks to alert us is that for a while the toolroom was legitimately quoting delivery dates into the factory in week numbers up to 66.