Decision Trees, Decision Tables, and Structured English

Decision Trees, Decision Tables, and Structured English are tools used to represent process logic.

The two building blocks of Structured English are (1) structured logic or instructions organized into nested or grouped procedures, and (2) simple English statements such as add, multiply, move, etc. (strong, active, specific verbs)

Five conventions to follow when using Structured English:

1. Express all logic in terms of sequential structures, decision structures, or iterations.
2. Use and capitalize accepted keywords such as: IF, THEN, ELSE, DO, DO WHILE, DO UNTIL, PERFORM
3. Indent blocks of statements to show their hierarchy (nesting) clearly.
4. When words or phrases have been defined in the Data Dictionary, underline those words or phrases to indicate that they have a specialized, reserved meaning.
5. Be careful when using "and" and "or" as well as "greater than" and "greater than or equal to" and other logical comparisons.

Four major steps in building Decision Trees:

1. Identify the conditions
2. Identify the outcomes (condition alternatives) for each decision
3. Identify the actions
4. Identify the rules.

Decision Tables are useful when complex combinations of conditions, actions, and rules are found or you require a method that effectively avoids impossible situations, redundancies, and contradictions. Decision Trees are useful when the sequence of conditions and actions is critical or not every condition is relevant to every action.

Three Basic Computer Programming Constructs:

1. Sequence
2. Selection (If-Else Conditional)
3. Iteration (Loops)