Scrum Principles¶

The working ideas behind the Scrum framework.

The classic summary¶

Development work is partitioned into "packets", meaning small, independently valuable backlog items rather than phases.
Testing and documentation are on-going as the product is constructed, not a phase bolted on at the end.
Work occurs in Sprints and is derived from a backlog of existing requirements.
Meetings are very short and, traditionally, sometimes conducted standing up, and the discomfort is the timebox.
Demos are delivered to the customer within the time-box allocated.

The pillars¶

Scrum is an empirical process: it assumes you cannot know the plan up front, so you inspect reality frequently and adapt.

Pillar	Meaning	Where it lives
Transparency	The work and its state are visible to everyone involved	Backlogs, Definition of Done
Inspection	Progress and artifacts are examined frequently	Daily Scrum, Sprint Review
Adaptation	What inspection reveals changes what happens next	Backlog re-ordering, Retrospective

Removing any one pillar breaks the other two: you cannot inspect what is not transparent, and inspection that changes nothing is theatre.

The empirical loop¶

graph LR
    T[Transparency: work and state are visible] --> I[Inspection: examined frequently]
    I --> A[Adaptation: what is found changes what happens next]
    A --> T

Each pillar depends on the previous one. You cannot inspect what is not transparent, and inspection that changes nothing is theatre.

The five values¶

Commitment, Focus, Openness, Respect, Courage. These are what make the events useful rather than ritual. A Retrospective without openness produces nothing, and a Daily Scrum without courage hides blockers until it is too late.

Empirical vs. predictive¶

	Predictive (plan-driven)	Empirical (Scrum)
Assumption	Requirements can be known up front	Requirements are discovered by building
Control	Conformance to the plan	Frequent inspection of a real Increment
Response to change	Change request, re-baseline	Re-order the Product Backlog next Sprint
Risk surfaces	At integration or acceptance	Every Sprint

Check Your Understanding¶

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Scrum is called an "empirical" process. What does that mean in practice?

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A team runs Retrospectives but never changes anything as a result. Which pillar is broken?