The purpose of the software integration and integration test process is to integrate the software units into larger software items up to a complete integrated software consistent with the software architectural design and to ensure that the software items are tested to provide evidence for compliance of the integrated software items with the software architectural design, including the interfaces between the software units and between the software items.

LDRA static analysis tools contribute to the verification of the design by means of the control and data flow analysis of the code derived from it, providing graphical representations of the relationship between code components for comparison with the intended design (Figure 8). A similar approach can also be used to generate a graphical representation of legacy system code, providing a path for additions to it to be designed and proven in accordance with ASPICE principles.

Figure 8: Diagrammatic representations of control and data flow generated from source code by the LDRA tool suite aid verification of software architectural design

Integration testing is designed to ensure that when the units are working together in accordance with the software architectural design, they meet the related specified requirements. It is desirable for all dynamic testing to use environments that correspond closely to the target environment and hence test dependencies between hardware and software.

Within the LDRA tool suite, unit tests become integration tests as units are tested as part of a call tree, rather than in isolation. Exactly the same test data can be used to validate the code in both cases.

The inputs and expected outputs defined in the test cases are typically derived from requirements to ensure intended functionality is verified. Various other forms of tests including negative tests, fault injection and robustness tests are available using the same mechanism.

The analysis of boundary values can be automated using an “extreme test” facility to automatically generate a series of unit test cases. The same facility also provides a facility for the definition of equivalence boundary values such as minimum value, value below lower partition value, lower partition value, upper partition value and value above upper partition boundary. Features like automated stub management, global variable declarations, and exception handling help to complete a comprehensive unit test facility

SWE.5 Software Integration and Integration Test