Implement additive, semi-additive, and non-additive measures

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Additive
Additive measures are numeric values that can be summed up by all the dimensions in the fact table, for example the Sales Amount. These are the most common measures and they are the easiest to understand and implement.

Semi-additive
Semi-additive measures are numeric values that can be summed up by some dimensions in the fact table, but not all. In most cases, they can be aggregated by any other dimension except time. 

An example of a semi-additive measure is Account Balance. You can determine the ending balance of an account at the end of a month, but adding up these monthly account balances do not make sense. Semi-additive measures are usually found in fact tables that store periodic snapshots of data.

Non-additive
Non-additive measures, as the name implies, are measures that cannot be summed up. These measures include percentages such as Discount Percent, ratios such as Profit Margin, and averages such as Average Unit Cost.
Exam 70-767

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