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.

Reference:

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)