Decision table

Each decision corresponds to a variable, relation or predicate whose possible values are listed among the condition alternatives.

To make them more concise, many decision tables include in their condition alternatives a don't care symbol.

[5] Aside from the basic four quadrant structure, decision tables vary widely in the way the condition alternatives and action entries are represented.

In other words, balanced decision tables prescribe an action in every situation where the input variables are provided.

[9][10] Decision tables have proven to be easier to understand and review than code, and have been used extensively and successfully to produce specifications for complex systems.