Review is the bottleneck

Show why work waits: one column with a low limit and slow reviews.

READY      7   DESIGN   4/4   REVIEW   2/2   BUILD    0/4   DONE      12
────────────   ────────────   ────────────   ────────────   ────────────
▒▒▒▒▒ ▒▒▒▒▒    ▒▒▒▒▒ ▒▒▒▒▒    ▓▓▓▓▓ ▓▓▓▓▓                   ▓▓▓▓▓ ▓▓▓▓▓
▒▒▒▒▒ ▒▒▒▒▒    ▒▒▒▒▒ ▒▒▒▒▒                                  ▓▓▓▓▓ ▓▓▓▓▓
▒▒▒▒▒ ▒▒▒▒▒                                                 ▓▓▓▓▓ ▓▓▓▓▓
▒▒▒▒▒                                                       ▓▓▓▓▓ ▓▓▓▓▓
                                                            ▓▓▓▓▓ ▓▓▓▓▓
                                                            ▓▓▓▓▓ ▒▒▒▒▒


                              ▲ Review holds everything up

Sample data: made up to show the idea, not real numbers

Source: Illustrative.