# Table 6

Buy or own: a classification of components. A judgment, not a measurement.

| Component | Classification | Why |
|---|---|---|
| Retrieval engines (hosted or open source) | Buy | Mature, broadly staffed, and the hardest part to build well |
| Merchandising console | Buy | Rule authoring, schedules and approvals are sold and supported |
| Product-information and content systems | Buy | Typed attributes and taxonomies ship off the shelf |
| Conversational front end | Buy, if grounded in the catalog | Language is not the differentiator; grounding is |
| Policy engine with decision logs | Buy | Evaluation and logging are solved; the policies are not |
| Protocol adapters (tool servers, feeds, checkout) | Buy | The protocols change monthly; vendors track them |
| Concept registry and typed relation vocabulary | Own as data, hosted in a bought product-information or taxonomy system | Meaning must outlive any one vendor |
| Content-typing schema and the map of systems of record | Own as data | They define what counts as evidence and where each fact comes from |
| Declarative strategy stacks | Own as data, compiled into engine rules where the placement test allows | The strategy is the business's; its execution may be the vendor's |
| Result-set contract, assembly and rendering of the canonical answer | Own as code | No single product can sell the agreement between products |
| Label joins, gates that must replay, cross-vendor decision records | Own as code | Replay must survive a change of vendor |