Many workplaces (especially public service jobs) have a system of "flex time" wherein you work on average about 7 hours a day, which means you can work longer hours on some days and then shorter hours (or not at all) on other days.
The system of keeping track of your working hours is your own responsibility.
This
leads to two problems: 1. it's a hassle to keep track of every time you come and go. 2. some people may cheat (saying they worked longer than they actually did).... (don't get me started about that...)
Automating the employee tracking system would overcome these problems.
This could be done with an ID system (eg you swipe your card to enter or exit the building). But this would require installation of equipment etc.
Instead, employees computer usage could be monitored and logged and "flex sheets" are filled out automatically.
(This is based on the assumption that most of your work is computer based.)
This could be over-ridden if you were in the office but not using your computer (ie meetings, reading etc).
Actually, this sounds too obvious... must have been done before???