Reliable inboxes are powerful because they let us Close open loops and focus on the work itself, rather than on meta-work.
But this story seems to recur constantly:
Inboxes only let us Close open loops if they’re reliable—that is, if you can add something to it with total confidence that it’ll get “handled” in some reasonable timeframe. “Handled” is fuzzy: you just need to feel that the fate of those items roughly reflects your true preferences. You’ll trust an inbox system which ends up dropping 90% of items if the other 10% were the only ones you really cared about. You won’t trust an inbox system in which 90% of tasks get done, but the 10% which don’t get done are the ones you really cared about.
In efficient inboxes, it may be easy to maintain this kind of confidence: the departure naturally rate exceeds the arrival rate. But most knowledge worker inboxes don’t look like this. The rates are highly variable, which creates bottlenecks. Not every item actually needs to get handled, but people are over-optimistic, so items accrue in a backlog.
Sometimes we can decrease the arrival rate; see e.g. Beware automatic import into the reading inbox. Usually we must also increase the departure rate, which is hard; see e.g. Triage strategies for maintaining inboxes (e.g. Inbox Zero) are often too brittle.
Matuschak, A. (2019, December). Taking knowledge work seriously. Presented at the Stripe Convergence, San Francisco.