Systems Atlas Project
METHOD Six rules, eleven lenses
How a system is divided, and what may then be asked of a part.
Two separate things. The six rules govern the division. The eleven lenses govern the questions put to what the division produced.
Rules
Six rules a division has to survive.
The rules are deliberately restrictive. Most of the work is throwing out divisions that felt right and then failed one of them.
At most seven
A division holds at most seven components, so the whole set can be compared in one go. The bound comes from Miller (1956).
Mutually exclusive
No component may share elements with another, and anything derivable from other components is not a component. Where assignment is ambiguous, the definitions are wrong and get tightened.
Collectively exhaustive
The components cover as much of the parent as at most seven of them can. This is exhaustive within a cognitive limit, not in the absolute sense, and the shortfall is recorded rather than hidden.
Equal abstraction
Components at the same level answer the same type of question. The level is argued from evidence where evidence exists, not settled by preference.
Decomposable or terminal
A component either splits into two or more non-overlapping parts, or it is an endpoint node. Subcomponents inherit the parent definition and add one of their own.
Justified in writing
Every category carries a definition, inclusion criteria, exclusion criteria, sources and boundary cases. A category without them is unfinished, whatever it looks like on the map.
Rules 1, 5 and 6 are checked by the validator and reported on every node page. Rules 2, 3 and 4 are judgements about meaning and cannot be automated — no state is claimed for them.
Lenses
Dividing a system is not the same as interrogating one.
The rules above govern how a system is cut into parts. They say nothing about what may then be asked of a part. Conflating the two is how most system descriptions go wrong — a structural claim defended with behavioural evidence, or a value judgement dressed as a description.
Every question put to a component is asked through exactly one of eleven lenses, declared in advance. The lens fixes what kind of answer counts and what kind of evidence can settle it.
Each lens carries its own exclusions. Mechanism hands motivation to Incentives; Incentives hands formal authority to Governance; Implementation hands the reasons it fails to Failure analysis. A lens is defined as much by what it refuses to answer as by what it covers.