At its simplest, it's really a flexible 'to do' list, all in one place. Some people make it into something more creative, colourful and expressive. It's a personal thing, which probably explains its rise in popularity, and so it's possible to adapt it to audio drama management.
Audio books - often 8-10 hours long plus, as Karen Commins mentions on her very informative blog, will take six times that many hours as a conservative estimate to produce. So you will be dealing with projects of around 60 hours.
That may take a lot of accurate planning to fit into your daily schedule.
I have always used very detailed breakdowns of the process in tables, colouring in progress as I go, alongside a calendar schedule, all online.
The bullet journal appealed to me in that it is a visual approach, but also a handwritten one. There is a fascinating article here by Lauren E (Cugliotta) Proctor, citing many pieces of research suggesting that "handwriting may play a role in superior synthesis and retention of complex ideas."
Whatever the reasons, I personally find physically ticking a box or scrawling a quick note can be satisfying.
So, I set about making a Bullet Journal style audio book production overview. In line with the movement, it's freehand rather than drawn up digitally. Many Bullet-journal creators seem to draw new designs for every project, but frankly it's less time-consuming to do it once and scan it.
Here is the page I came up with, which contains basic information and progress boxes, so that it's quick to fill in, and it fits neatly into an A5 size notebook. It may be worth doing a longer, more detailed character breakdown, perhaps with any pronunciation queries for the rights holder (if necessary). But this just allows for a very immediate overview of the state of progress and the number of hours' work remaining.
If you're also wooed by this approach, then have fun designing your own, personalised work schedule!