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Inventory as Buffer and Liability

Why It Matters

The right amount of inventory is not zero and not infinite. Understanding what inventory does helps you choose where to hold it and how much.

The Key Move

Ask what function the inventory serves. Is it buffering variability? Enabling batch efficiency? Hedging supply uncertainty? Then ask what it costs: capital, space, obsolescence risk, problem-hiding.

Classic Application

Manufacturing. Work-in-progress inventory buffers variation between machines but also hides quality problems (defects aren't discovered until downstream).

Surprising Application

Information backlogs. Your email inbox is inventory. It buffers arrival variability but also hides priorities and ties up attention. Slack message queues, todo lists, browser tabs - all inventory with similar dynamics.

Failure Modes

  • Treating all inventory as waste
  • Holding inventory that doesn't serve a buffering function
  • Using inventory to avoid solving underlying variability problems

Go Deeper

Ohno's "Toyota Production System." Lean manufacturing literature.