Inspect and adapt is the core Agile feedback loop: examine what is actually happening, then adjust based on what you find. The phrase is most strongly associated with scrum and empirical-process-control, but the underlying pattern is present in every Agile method. kent-beck's extreme-programming runs the loop through the test suite; alistair-cockburn's crystal runs it through "reflection workshops"; the agile-manifesto-twelve-principles express it in principle 12 as regular retrospection and adjustment.
Intellectual Roots
The inspect-and-adapt loop is a specific instance of a much older idea in control theory and organizational learning. W. Edwards Deming's Plan-Do-Check-Act (PDCA) cycle, later revised to Plan-Do-Study-Act (PDSA), is the most direct predecessor: plan an experiment, execute it, study the results, act on what you learned. Deming developed PDCA from Walter Shewhart's statistical process control work, which itself was rooted in the experimental method.
The pattern also appears in John Boyd's OODA loop (Observe-Orient-Decide-Act), which describes how effective decision-makers maintain tempo by cycling through observation and adaptation faster than their adversaries. responding-to-change — the fourth Agile value — is the strategic expression of the same logic: the team that can observe reality and adapt faster than the competition gains an advantage.
Scrum's Implementation
ken-schwaber and jeff-sutherland built inspect-and-adapt into every level of Scrum's structure:
This multi-timescale structure distinguishes Scrum's implementation from simpler "check in occasionally" approaches. Inspection without adaptation is measurement theater; adaptation without inspection is arbitrary change. The pairing is what produces learning.
Relationship to definition-of-done
Inspection requires a standard against which to inspect. The definition-of-done serves this function: it establishes what "done" means so that inspection of the Increment has a fixed reference point. Without it, inspection becomes subjective and adaptation is disconnected from reality. This connection — inspect-and-adapt requires transparency, and transparency requires shared definitions — is why the three pillars of empirical-process-control (transparency, inspection, adaptation) are named in that order.
Beyond Scrum
The agile-manifesto-twelve-principles' principle 12 states the pattern without Scrum-specific language: "At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly." The retrospective is the primary ceremony for this, and esther-derby (with Diana Larsen) systematized retrospective facilitation as a discipline. The heart-of-agile's "Reflect" and "Improve" — two of alistair-cockburn's four words — are direct descendants. The pattern is what survives when frameworks are stripped away.