Spec

Functional and technical specification for this initiative.

Scope

M1 should prove that the chart library can support repeated analyst use with a deliberately small but coherent chart batch. The milestone is not "many charts" and not yet "full chart-system maturity"; it is "enough working chart coverage to support a real pilot workflow."

Recommended Basic Chart Batch

Required: - table - KPI - bar - column - line - pie - donut

Recommended if implementation is thin because the grammar is already close: - area - scatter

KPI is worth explicitly including even though it is not a classical chart mark, because pilot dashboards usually need a summary readout alongside the other views. Area and scatter should stay behind the core set unless they are truly low-friction extensions.

Sequencing

The recommended milestone sequence is:

1. M1 establishes the basic chart batch.
2. M2 adds style packages, evaluation ownership, design assertions, semantic type behaviors, exposed properties, and a good table chart baseline.
3. M3 pushes into starter dashboard composition and data-informed chart properties.

Exit Signal

M1 is complete when a pilot analyst can produce and reuse a small set of core charts from the basic batch in a real workflow, and the chart-library team has a clear, explicit handoff into the next milestone-linked initiatives rather than trying to solve style systems, evaluation, assertions, and dashboard composition all at once.