Watch For Clashes
Name the one property that must never break; let everyone change things at once; step in only where two changes would break it together.
Formerly Confluence
A braided river: channels split and rejoin; only the banks constrain.
Seen in Yona Friedman, Flatwriter, conceived for an exhibition in Osaka, 1970
Try it on your work
Let several people change the thing you're working on at once without coordinating. Name the one property that must never break. Intervene only when two changes would break it together. Stop when the work is full and the property holds; count how many interventions it took, and that is the true coordination cost.
Let two people edit the same text without talking. Fix one rule: no sentence may contradict another. Merge. Resolve only the contradictions. Stop when the merged text has none; everything else stands as written.
Remove every sync meeting from a week and replace it with one invariant everyone knows. Intervene only when two people's work would violate it. Stop at the week's end and compare the number of interventions with the number of meetings they replaced.
How it has been used
A braided river splits and rejoins constantly, and no one coordinates the channels; only the banks constrain it. Some collaborative software works the same way: everyone edits independently, and the pieces are built so that merging cannot conflict.
Where it leads
Grouped under Help the parts work together