Identify which decision factors are "key"

For a non-trivial product, the eligibility/entitlement calculations are likely to be complex, with many layers and interactions.

Ultimately each of these calculations has a bearing on the overall eligibility/entitlement result; however, you must decide which of these results are "key" to aiding a case worker's understanding of a case. You might prepare a candidate list of key decision factors and discuss them with your business experts and/or senior end-users.

If you identify too few key decision factors, then case workers might not be able to readily understand a determination. By contrast, if you identify too many key decision factors, then the key decision view may become too cluttered for case workers to easily use. In particular, take care to distinguish candidates for key decision factor output from requirements for decision details (which are amenable to more detailed display - see Calculating and Displaying Decision Details).

For example, let's say you have a product where a household is means tested, by comparing the total household income against a set of income thresholds.

The total household income is calculated by adding up the total household income for each person in the household. Moreover, each person can have many concurrent employments (e.g. a day job, a night job and/or a weekend job) and so the total income for each person is calculated by adding up the earnings from each income.

In this example, the following are candidates for key decision factors:

• which income threshold the household falls into;
• the income thresholds themselves (which happen to be constant across all products - still potentially useful to show to the case worker, though);
• the total household income;
• for each person in the household, the total person income;
• for each income, the earnings for that income, and the dates that the income started and ended.

An implementation which included all of the above key decision factors could well be too cluttered to use, so business analysts producing requirements for key decision factors must choose carefully.