The system of interfaces and implementations involved in the calculation of the key decision factors that form part of a determination result follow a similar pattern to that for eligibility/entitlement calculations (see Calculation of Eligibility and Entitlement).
The responsibilities for calculating a case's key decision factors are divided between fixed implementations provided by the application and custom implementations for a product (some of which must adhere to interfaces included with the application).
Sections A and E describe a layer of fixed implementations similar to that of the eligibility/entitlement calculations, and contribute to calculating and storing the overall determination result, which includes the key decision factors. Although not described below, this layer also includes the calculation of contributing product periods.
The processing described in sections B, C, and D represents a combination of fixed interfaces and custom product-specific processing that is responsible for determining the key decisions factors across product periods.
Similar to eligibility/entitlement calculations, section B describes a fixed interface included with the Engine and sections C and D both describe custom product-specific processing.
Although not described below, the fixed implementation and fixed interfaces contributed by the engine that are responsible for retrieving the data from entities, evidence and rate tables for eligbility/entitlement calculations are also used by the custom product-specific processing described in section D.