Interesting thought. One could do Monte Carlo simulations to estimate the probability distribution of time-to-finish. I considered something like this [0] to explain the empirical log-normal distribution of project completion times [1], although I hadn't thought about including sequencing & bottlenecks. Probabilistic programming [2] is the discipline concerned with solving this type of problem - some tooling might exist, although probably w/o a nice UI.

[0] https://heteroskedasticblog.wordpress.com/2021/12/04/softwar...

[1] https://erikbern.com/2019/04/15/why-software-projects-take-l...

[2] https://en.wikipedia.org/wiki/Probabilistic_programming