4.44 Elementary Method "White Box Test Case Design" (WBTD)

  4.44 Elementarmethode "White-box-Testfallentwurf" (WBTE)

Contents		1 Identification/Definition of the Method 2 Brief Characteristic of the Method 3 Limits of the Methods Application 4 Specification of the Methods Allocation 5 Interfaces 6 Further Literature 7 Functional Tool Requirements Links to the V-Model Mailinglist

1 Identification/Definition of the Method

2 Brief Characteristic of the Method

The objective of the "White Box Test Case Design" (WBTD) is to detect errors by means of execution-oriented test cases.

Operational Sequence

White Box Testing is a test strategy which investigates the internal structure of the object to be assessed in order to specify execution-oriented test cases on the basis of the program logic. In this connection the specifications have to be taken into consideration, though. In a test case design, the portion of the assessed object which is addressed by the test cases is taken into consideration. The considered aspect may be a path, a statement, a branch, and a condition. The test cases are selected in such a manner that the correspondingly addressed portion of the assessed object is increased.

The following White Box Test Case methods exist:

1. Path Coverage

   Objective and Purpose
   It is the objective of the path coverage to identify test cases executing a required minimum number of paths in the object to be assessed. The execution of all paths cannot be realized as a rule.

   Operational Sequence
   By taking into consideration the specification, the paths to be executed and the corresponding test cases will be defined.

2. Statement Coverage

   Objective and Purpose
   It is the objective of the statement coverage to identify test cases executing a required minimum number of statements in the object to be assessed.

   Operational Sequence
   By taking into consideration the specification, statements are identified and the corresponding test cases are defined. Depending on the required coverage degree, either all or only a certain number of statements are to be used for the test case definition.

3. Branch Coverage

   Objective and Purpose
   It is the objective of the branch coverage to identify test cases executing a required minimum number of branches, i. e. at least once in the object to be assessed.

   Operational Sequence
   By taking into consideration the specification, a sufficiently large number of test cases must be designed by means of an analysis so both the THEN and the ELSE branch are executed at least once for each decision. I. e. the exit for the fulfilled condition and the exit for the unfulfilled must be utilized and each entry must be addressed at least once. For multiple decisions there exists the additional requirement to test each possible exit at least once and to address each entry at least once.

4. Condition Coverage

   Objective and Purpose
   The objective of the condition coverage is to identify test cases executing a required minimum number of conditions in the object to be assessed.

   Operational Sequence
   By taking into consideration the specification, conditions are identified and the corresponding test cases are defined. The test cases are defined on the basis of a path sequence analysis.

5. Branch/Condition Coverage

   Objective and Purpose
   The objective of the branch/condition coverage is to identify test cases executing a required minimum number of branches and conditions in the object to be assessed.

   Operational Sequence
   By taking into consideration the specification, branches and conditions are identified and the corresponding test cases are defined.

6. Coverage of all Multiple Conditions

   Objective and Purpose
   The objective of the coverage of all multiple conditions is to identify test cases executing a required minimum number of all possible condition combinations for a decision in the object to be assessed.

   Operational Sequence
   By taking into consideration the specification, condition combinations for decisions are identified and the corresponding test cases are defined. When defining test cases it must be observed that all entries are addressed at least once.

3 Limits of the Methods Application

4 Specification of the Methods Allocation

5 Interfaces

6 Further Literature

7 Functional Tool Requirements

Links to the V-Model Mailinglist

This page online  •  GDPA Online  •  Last Updated 06.Mar.2003 by C. Freericks