The problem: the roster lives in three places at once
In most growing security companies the roster exists as a spreadsheet in the office, a printed deployment sheet at each site, and a running set of WhatsApp messages that amend both. All three disagree by the middle of the week.
The cost shows up at month end, when payroll is reconciled against a roster nobody trusts. Hours get paid that were never worked, hours get worked that were never billed, and the argument about which is which takes days.