What is Decision Table and Decision Tree in Software Engineering
Decision Table in Software Engineering:
A decision table shows the decision making logic and the corresponding actions taken in a tabular or a matrix form. The upper rows of the table specify the variables or conditions to be evaluated and the lower rows specify the actions to be taken when an evaluation test is satisfied. A column in the table says a rule. A rule implies that if a certain condition combination is true, then the corresponding action executed.
Decision Tree in Software Engineering:
A decision tree gives a graphic view of the processing logic involved in decision making and the corresponding actions taken. Decision tables specify which variables are to be tested, and based on this what actions are to be taken depending upon the outcome of the decision making logic, and the order in which decision making is performed. The edges of a decision tree represent conditions and the leaf nodes represent the actions to be performed depending on the outcome of testing the conditions.
Example: A library membership management software (LMS) should support the following three options—new member, renewal, and cancel membership. When the new member option selected, the software should ask for the member’s name, address, and phone number. If proper information entered, the software should create a membership record for the new member and print a bill for the annual membership charge and the security deposit payable. If the renewal option chosen, the LMS should ask for the member’s name and his membership number and check whether he is a valid member. The decision tree representation for this problem is shown below figure: