Why spreadsheets stop working sooner than expected
In most plants the first safety system is a set of files: one for training dates, one for medical checks, one for the incident log, one for actions after inspections. Each is correct on its own. The problem appears when they must be combined — that is the only moment you notice that a transferred employee holds valid periodic training but no referral for the examination required by the new hazards.
The second cost is duplicated work. The same person is entered in five places, and a job change requires five corrections. In practice someone always misses one, so the files disagree and nobody can say which one is current.
The third cost is the least visible: no history. A spreadsheet shows today's state and overwrites yesterday's. A year later, when someone asks exactly when a control measure was introduced and who approved it, the answer has to be reconstructed from email.


