The standard
Four documents, one argument
Read in this order: the charter if you own buildings, clause 2 and clause 16 if you are going to implement it, the decision record if you think the model is shaped wrong.
Founding charter
Why this exists, what it refuses to do, and the boundary between what the owner keeps and what the vendor keeps.
Specification — BUS-1 v0.2
The normative document: core model, portable presentation, exchange package. Twenty clauses, five annexes, 56 conformance tests.
Decision record
Forty-six decisions with what was chosen, what was rejected, and why. Written so an architect can lose an argument with us in private.
Roadmap & open issues
What is settled, what is provisional, what is unspecified, and what is deferred to BUS-2. No dates.