How a Determination Result Is Calculated

A determination result is calculated by the execution of a chain of CER rules.

These rules fall into two categories:

• Fixed Rules

  The Engine includes some fixed rules which cannot be customized. These rules are responsible for calculating the determination over different legislative periods, and for creating product-specific rule objects for the execution of product-specific rules.

• Product-Specific Rules

  Each product will have rules which contain the business and technical logic for the calculation of eligibility/entitlement and explanations for that product. These rules also effectively link the product to types of evidence, personal data and rates to be used in determination calculations for the product.

A high-level summary of the chain of CER rules execution for a determination is as follows:

• the case's lifetime is calculated, with reference to its actual and expected start and end dates;
• the case's lifetime is checked against the product periods for the product, to see which of these periods overlap with the case's lifetime. These product periods will contribute to the case's determination (any other product periods lying wholly outside the case's lifetime are ignored);
• for each contributing product period, product-specific rule objects for the case are created (one rule object for the case's eligibility/entitlement, optionally¹one rule object for key decision factors, and one rule object for each category of decision details²), according to the configuration of the product period;
• for each product-specific rule object created, its output attribute values are calculated to get the eligibility/entitlement/explanation results for a portion of the case's lifetime;
• the calculation of eligibility/entitlement/explanation results will involve the execution of lower-level rules, which may perform searches to retrieve personal data, evidence and/or rate data. These searches effectively link the case to the input data on which the case determination result ultimately depends.
• the results arising from different product periods are then "spliced together" to arrive at an overall determination result which covers the full lifetime of the case.