To me, it's not a checkbox so much as it is a tri-state progress bar: no progress, some progress, complete; and also the outlining of them sounds much like a compressed gantt chart [0]. As for the idea and power of lists, there's a great talk by Atul Gawande on Youtube[1], which I'd highly recommend.

[0]: https://en.wikipedia.org/wiki/Gantt_chart

[1]: https://www.youtube.com/watch?v=dfl8Xt8W09A