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Dependency Ordering

Arrange actions or components according to prerequisite dependencies so later steps do not begin before required conditions exist.

The Diagnostic Story

Symptom: Work is started in good faith and then discovered to be blocked: the required predecessor was not yet complete. Rework cascades through downstream steps because something upstream was assumed but not confirmed. The process sometimes works and sometimes fails depending on who remembers the correct sequence. Dependencies are implicit, spread across people and tools, and recalled informally.

Pivot: Map the prerequisite relations explicitly, impose a partial or total order that reflects them, and enforce prerequisite satisfaction before any step is permitted to proceed. Hidden order constraints become visible structure.

Resolution: Steps no longer begin before required conditions exist, so rework from missing predecessors drops sharply. The process produces consistent results regardless of who runs it, and blocked downstream work becomes detectable — and preventable — early.

Reach for this when you hear…

[construction] “You can't frame the walls until the foundation is cured — I don't care how far behind schedule we are.”

[software deployment] “The migration has to run before the service starts, not after — we've re-learned that the hard way three times now.”

[regulatory approval] “We can't submit the Phase III data until Phase II is signed off — building that package now is work we'll just have to redo.”

Mechanisms / Implementations

  • Dependency Graphs: A dependency graph is a representation mechanism.
  • Topological Sort: Is an algorithmic mechanism for producing a valid order from an acyclic dependency graph.
  • Critical Path Method: Implements a time-sensitive variant of Dependency Ordering.
  • Prerequisite Matrix / Prerequisite Matrices: A prerequisite matrix lists each unit of work against required predecessor conditions, owners, evidence, and allowed next actions.
  • Deployment Runbooks: A deployment runbook operationalizes Dependency Ordering in systems operations.
  • Curriculum Prerequisite Maps: A curriculum prerequisite map uses Dependency Ordering in learning design.
  • Treatment Sequencing Protocols: A treatment sequencing protocol orders clinical actions around diagnostic, stabilization, consent, contraindication, and safety prerequisites.
  • Manufacturing Process Plans: A manufacturing process plan sequences preparation, tooling, inspection, transformation, and assembly steps around physical and quality dependencies.
  • Curriculum Prerequisite Map
  • Dependency Graph: Draws the system's depends-on relations as nodes and directed edges so concentration, chains, and single points of failure become visible at a glance.

Abstractions this archetype builds on — directly (a source ingredient) or as a related pattern. Links follow the typed catalog namespace.

Built directly on (3)

  • Order: Defines ranking or sequencing relationships.
  • Pipeline: Sequential processing stages.
  • Well Foundedness

Also references 5 related abstractions

  • Causality: Cause-effect relationships.
  • Constraint: Limits possibilities to guide outcomes.
  • Hierarchy: Organizes elements into levels or ranks.
  • Network: Models interactions between components.
  • Relation: Describes associations or dependencies.

Variants

Narrower or domain-specific specializations that share this archetype's core structure. Recognized variants are established; candidate variants are provisional.

Prerequisite-Gate Ordering · governance variant · recognized

Uses explicit gates to prove prerequisites are satisfied before dependent work advances.

Critical-Path Dependency Ordering · temporal variant · candidate

Orders dependent work while highlighting the dependency chain that controls total duration, risk, or delivery timing.