Distributions and divisors

The approved budget controls the distribution. The service resolves and freezes the divisor used for each point calculation so a later policy change cannot alter old evidence.

Components use Derived divisors from the distribution, an Explicit controlled divisor, or a Source coverage factor that converts a frozen expanded-uncertainty source. The sensitivity coefficient scales standard uncertainty into its contribution. Source values retain their units; the engine converts compatible uncertainty contributions into the budget output unit. A conversion does not establish a missing source or a different measurement model.

The definition shows the saved divisor mode; calculation evidence shows the resolved numeric divisor and contribution. Do not treat an absent work input as zero. Type A repeated observations derive their divisor and degrees of freedom from the retained readings. For Type B components, an omitted finite degrees-of-freedom value means the model assumes infinity; it is displayed explicitly.

Choose a resolution distribution from the declared source and model with qualified review. A rectangular model commonly represents a bounded interval, whose entered magnitude must match the model's half-width. New resolution components propose rectangular; existing Normal components remain unchanged until a controlled revision is reviewed and approved.