Get something like this (but even more useful):
- Less time spent doing boring stuff: searching for bottlenecks on complicated production lines, forecasting changes to production lines, etc.
- More time doing fun stuff: change stuff (e.g. belt layout) and see how it affects output at all stages of production
For instance, if you're producing Science Pack 2, and the assembly machine building the inserters runs out of iron plate, it takes a while to sort though things to find the problem (stoppage). Similarly, if you forget to add enough inserters between the Copper Cable and Electronic Circuit, you'll still get Science Packs, just at a much slower rate (bottleneck).
While there are fancy visualizations that might work really well for something like this (alluvial diagrams maybe), a tweak to Max Rate Calculator might add a lot of utility: letting the player select/deselect machines from a list of those they selected. Imagine getting a list of all the assembly machines from a Science Pack 2 production line, and being able to select individual machines. Doing so would update the production report UI with inputs/output for the production line serving as input to that machine.
Here's some prior art: