To the Bedrock
The Garbage Can Model

Explore

Run the Garbage Can Model with any parameter combination. Adjust problem difficulty, how problems surface, decision structure, and access structure to see how different configurations shape decision-making.

The Garbage Can Model

Choice opportunities are the large circles: meetings, reviews, or committees where decisions can happen. Problems are the small dots: they arrive, seek an accessible opportunity, and may move between opportunities. Participants are represented through the effort they contribute, rather than individual figures. The blue-grey arc around each active circle shows accumulated effort relative to its current problem demand; a choice closes when effort meets demand.

This explorer simplifies the model's four streams. Solutions are represented by a fixed effectiveness setting in participants' effort, rather than separate moving objects. Green dots are problems inside a choice opportunity, not solutions. A solid green closure outline means problems were solved; a dashed blue-grey outline means the choice closed without solving any. The green fill records the cumulative number of problems solved there, not participant effort. Open “How to read this animation” for the two legends.

Watch the sequence: arrivals, problem movement, participant attention, then closure. Problems and participants each favour accessible opportunities with the smallest remaining effort deficit; ties are random. This can leave difficult problems clustered elsewhere while easier opportunities close. Problems leaving before closure illustrate flight; an opportunity closing while problems are elsewhere illustrates oversight. Both can describe the same closure.

Ongoing issues emerge steadily through everyday work. Planning-period issues surface mainly during initial discovery and planning. A backlog arrives in a burst when an audit, incident, or organisational change brings accumulated concerns to attention. Problems that surface early may reach a meeting before it closes; later ones may find the budget already allocated or the review finished. Use Pause and Next stage to inspect the sequence, or select a problem to follow its path.

Every run contains 20 problems. This setting changes when they surface relative to decision opportunities.

Connections to operating practices

Frameworks shape when issues become visible and when they receive attention. The same organisation can experience continuous discovery, planning cycles, and sudden bursts of demand. These connections offer examples for the illustration; they do not assign each framework to one arrival pattern.

Ongoing issues. Regular customer contact in continuous discovery helps concerns surface throughout the work. Continuous-flow approaches such as Kanban provide a useful setting for exploring this kind of intake. Discovering an issue and starting work on it are separate decisions.

Planning-period issues. Scrum Sprint Planning and SAFe PI Planning bring priorities and proposed work into discussion; PI Planning also makes risks and dependencies visible. Planning groups existing issues for attention as well as revealing new ones. Scrum also includes ongoing backlog refinement, so issues can surface between planning events.

Backlog arrives in a burst. An incident, audit, or transformation review can bring accumulated issues to attention together. SRE postmortems, for example, identify corrective actions after an incident. A burst is a situation that can occur within any operating model.

Here, “surface” means becoming visible to the decision process. The illustration changes arrival timing; it does not simulate the frameworks themselves or distinguish issues by their origin.