How is it flowing?

How long does it take for GitHub pull requests and issues to flow through the development process? In other words, what is the cycle time?

Oselvar gives a quick overview of a project's cycle time distribution using yearly violin plots.

Publish your own Oselvar Metrics

Use a Cumulative Flow Diagram to gain more insight:

Approximate average cycle time (AACT)
Work in progress (WIP)
Throughput (departure rate)
Arrival rate

A CFD is not suitable for forecasting (unless the cycle time distribution follows a normal distribution, which is very unlikely). Instead, a CFD is a useful tool for reflecting about the past.