To the Bedrock
The Garbage Can Model

Taxonomy

The Garbage Can Model classifies organisations along three structural dimensions. Their combination determines how problems, participants, and choice opportunities interact — and what kind of decision-making emerges.

The Three Dimensions

Problem Pressure (Difficulty + Arrival Rate)

How much pressure the organisation carries relative to its capacity to process it. Pressure combines problem difficulty (effort per problem) and problem arrival rate (new problems per organisational iteration). High pressure means more problem-demand than the system can absorb.

Light: capacity typically exceeds demand. Most problems find closure. Moderate: capacity and demand are often in tension. Some problems close, others circulate. Heavy: demand overwhelms capacity. Choice opportunities often close without resolving underlying problems.

Decision Structure

Who gets to participate in which choice opportunities. This determines where attention and effort actually go.

Open participation (non-segmented): all decision makers can attend all choice opportunities. Energy spreads everywhere. Hierarchical: senior decision makers access more choice opportunities. Energy concentrates at the top. Specialized: each decision maker attends only their designated choice opportunity. Energy is siloed.

Access Structure

Which problems can reach which choice opportunities. This determines whether problems even reach places where they could be resolved.

Open (non-segmented): any problem can surface in any choice opportunity. Problems float freely. Hierarchical: important problems access more choice opportunities. Lower-priority problems are restricted. Specialized: each problem is assigned to exactly one choice opportunity. No migration possible.

The Classification Grid

Decision structure plus access structure gives the organisation type. Problem pressure changes how severe the pattern feels, but it does not change the type.

The five labels in this site are working diagnostic labels for Explorer and Assess. They help interpretation in this module; they do not replace the original model terms.

Open access Hierarchical access Specialized access
Open participation decision Complexity-Informed Inverse Mix Inverse Mix
Hierarchical decision The Mix Coherent Traditional The Mix
Specialized decision Inverse Mix The Mix Siloed

Some decision/access combinations intentionally map to the same cluster in Explorer and Assess.

The Five Types

The Coherent Traditional Organisation

Hierarchical decision · Hierarchical access

Problems usually reach the right forums. Decisions are made by the people expected to make them. Governance and reporting lines are mostly aligned with the work, so the system behaves close to its formal design. In this case, the Garbage Can Model has less explanatory power.

The Complexity-Informed Organisation

Open participation decision · Open access

What you notice first is permeability: problems surface in many places, and participation follows expertise more than rank. This is not disorder. It is a different operating logic. The main risk is traceability: decisions happen, but it is harder to see who decided what, and whether the original problem was solved or just moved.

The Mix

Hierarchical decision · Open or Specialized access

This is the common mismatch: emergent work, hierarchical decision rights. Problems emerge where the work happens, but authority sits elsewhere. So teams spend energy translating and escalating rather than resolving. The structural gap is persistent, not accidental.

The Inverse Mix

Open participation or Specialized decision · Hierarchical or Specialized access

Decision forums can be open or responsive once a problem gets in. The bottleneck is earlier: problem access is filtered. Edge problems travel slowly or not at all, so the room can be ready to decide but still decide the wrong things.

The Siloed Organisation

Specialized decision · Specialized access

On the org chart this looks clean: fixed channels, fixed owners, fixed forums. In practice, cross-cutting problems get stranded between boundaries. When no formal forum owns the issue, work either disappears from view or gets handled informally outside governance.

Explore Further

See the model in action or assess your own organisation:

Explore Run the model with any parameter combination Assess Answer twelve questions and see your organisation modelled What's a Garbage Can? Follow problems, solutions, and participants into one choice opportunity (CO)