FOREST | Overview | Product Model | Reference Model | Classification of Statements |
The distinction between what already exists and what still has to be developed has a great impact on the classification of the statements. We demand that each statement has to be exactly in one of the following two moods:
indicative mood: | A statement in indicative mood describes something in the real world as it is. |
optative mood: | A statement in optative mood describes something in the real world as it should be. |
When combining the mood of a statement with the scopes of the terms that occur in this statement, a large variety of different kinds of statements is possible, but only the following three disjoint combinations of mood and scope are reasonable:
domain statement: | a statement in indicative mood where all terms are visible to the environment (scopes eh, ev, or mv). |
requirement statement: | a statement in optative mood where at least one term with scope eh is used. |
machine statement: | a statement in optative mood where all terms are visible to the machine (scopes ev, mv, or mh). |