You have run static analysis tools against four large, complex code components (A, B, C,...

When deciding which component to select first for maintainability improvements, it's essential to prioritize the most critical factors. In this case, the combination of Cohesion and Coupling is the most important factor, followed by the number of repeated code sections.

Cohesion and Coupling:

High Cohesion and Low Coupling are desirable qualities in software components. High cohesion means that the component's responsibilities are closely related, making the component easier to understand, test, and maintain. Low coupling means that the component has fewer dependencies on other components, making it less prone to ripple effects from changes in other parts of the system.

Conversely, Low Cohesion and High Coupling indicate poor design quality. Low cohesion suggests that the component has many unrelated responsibilities, which can make it harder to maintain and understand. High coupling indicates that the component is highly dependent on other components, which can lead to more significant maintenance challenges due to the ripple effect of changes.

Number of Repeated Code Sections:

Repeated code sections are also an important factor because they can indicate code duplication, which can lead to inconsistencies and higher maintenance costs. Reducing the number of repeated code sections can improve maintainability by promoting reusability and reducing redundancy.

Based on the given measures:

Component A has high cohesion and low coupling, which are desirable. It also has a moderate number of repeated code sections (4).

Component B has low cohesion and high coupling, which are the worst in terms of design quality. It also has the highest number of repeated code sections (5).

Component C has low cohesion and high coupling, which are poor in terms of design quality. It has the lowest number of repeated code sections (2).

Component D has high cohesion and low coupling, which are desirable. It also has the highest number of repeated code sections (5).

Considering the most important factor first (Cohesion and Coupling):

Component B and Component C are both poor in terms of cohesion and coupling, but Component B is worse because it has a higher number of repeated code sections than Component C.

Component A and Component D are both good in terms of cohesion and coupling, but they are less critical to address first than the poor components.

Therefore, Component B should be selected first for applying maintainability improvements because it has the poorest combination of low cohesion and high coupling, along with the highest number of repeated code sections. This aligns with the prioritization criteria provided.

References:

The importance of Cohesion and Coupling in software design is well-documented in the ISTQB CTAL-TTA syllabus and other software engineering literature. (Refer to ISTQB-CTAL-TTA Syllabus v4.0)

The analysis aligns with the sample exam question and answer pattern found in the ISTQB CTAL-TTA Sample Exam Questions and Answers documents. (Refer to ISTQB_CTAL-TTA_Sample-Exam-Questions_v4.1 and ISTQB_CTAL-TTA_Sample-Exam-Answers_v4.1)