Fourth of Julia Barham's four scaling mistakes: not managing product and team capacity like a balanced portfolio. She divides work into four "slices of the pie":
Some teams deliberately reserve roughly 20% of capacity for the production-support slice so it doesn't get silently starved by the other three.
Related: Explore/Exploit Dual Portfolio Management, Three Buckets of Product Work: New, Existing, Protect Value, Four Types of Post-PMF Product Work (Reforge Framework), "Don't Scale Chaos" (Leader-as-Bottleneck Mistake) (sibling mistake).
A concrete implementation of the framework: proactively reserve roughly 20% of team capacity for production support / run-the-business work up front, rather than treating it as unplanned overflow that squeezes the other three slices (innovation, optimization, capability work). Budgeting the cost in advance converts an otherwise-inevitable interruption into a planned line item — the same move behind Separating Keep-the-Lights-On Work from Strategic Focus — and keeps support work from silently eating into strategic bets.