Explainability is whether you can say why the system produced that result, in terms a customer, an auditor, or a colleague will accept. A score is not an explanation. A reason is: these three late payments, this clause, this similar past case.
Ask how much explanation the decision needs before you pick the method. Approving a marketing subject line needs little. Declining a loan or flagging a patient needs a lot. If the best-performing model cannot give a reason you would say out loud, use a simpler approach or a person for that decision.
Think of it this way: Explainability is the AI equivalent of showing your work. A black box that gives the right answer sometimes is not the same as a system that can trace any answer back to its reasoning.
A bank deploys a loan rejection model. A regulator asks why a specific application was declined. Without explainability, the bank cannot answer. With it, the decline reason is traceable and documentable.
A customer asks why an application was delayed. The agent can see a score of 0.82 and nothing else, so they guess. After the team adds the top factors, the agent says the delay is two missing documents and names them. The customer knows what to send. The agent stops inventing a reason.
In any context with regulatory reporting requirements, credit decisions, medical diagnosis support, or anywhere users or auditors have a right to understand a decision that affects them. Requiring full explainability on every AI feature adds cost and complexity. Apply it where the stakes demand it. General recommendation engines have a much lower bar.
RaftLabs treats this as part of the build: a source on the answer, a test set, and a record of what the system did. The launch is the start of that work, not the end. The related work on our side is AI governance.
This sits with the other reliability & risk terms on the glossary. Why a confident answer can still be wrong, and how you catch it. Worth reading next: Hallucination, Guardrails, and Evaluation (evals).