I left the board up in a corridor along with instructions (which I've rephrased below) so that passers by could contribute:
1. Grab a pink sticky, write something that is making your job hard.
2. Grab a yellow stick, write "Why?", include an arrow.
Repeat steps 1 and 2 until you run out of pink stickies, or complications.
Grab a purple sticky if you want to challenge whether a complication you see written on a pink sticky is still true. This signals that we might be able to unravel that particular chain of misery.
Grab a green sticky in case you know of a candidate solution to a complication written on a pink sticky.
The anonymity of the stickies and the accessibility of the format really seemed to catch on. The size constraints of the stickies forced concise descriptions of the complications. Every time I walked past the board there were more stickies, describing more issues and their causes.