In software maintenance and regression testing, impact analysis mainly helps a test team decide which aspect of testing effort?

Introduction / Context:
Impact analysis is an important activity in software maintenance, change management, and regression testing. Whenever a change is requested, teams must understand how that change affects existing functionality, interfaces, and test assets. This question checks whether you recognize the main decision that impact analysis supports, especially in relation to the scope and depth of regression testing.

Given Data / Assumptions:

We assume a change has been made or proposed in an existing software system.
Impact analysis is performed before or during change implementation.
The goal is to plan what testing is required after the change, particularly regression testing.

Concept / Approach:
Impact analysis systematically examines which modules, interfaces, data structures, and test cases are affected by a proposed change. It is used to estimate the effort needed to safely implement the change. In testing, the main use of impact analysis is to decide the scope of regression testing. Regression testing checks that unchanged parts of the system still work correctly after changes. If impact analysis reveals that a change touches many modules or critical interfaces, the team must run a larger regression suite. If the impact is localized and low risk, the regression effort can be smaller and more focused, saving time but still maintaining quality.

Step-by-Step Solution:
Step 1: Identify the meaning of impact analysis in the context of software testing.Step 2: Remember that impact analysis evaluates how far a change spreads in the system and which areas are affected.Step 3: Connect this to regression testing, which retests existing functionality after a change.Step 4: Choose the option that explicitly refers to deciding the amount or extent of regression testing after a change.

Verification / Alternative check:
An alternative check is to recall the relationship between impact analysis and test planning. Impact analysis outputs a list of impacted components and test assets. Test managers use this list to determine which regression test suites to run, how many test cases to include, and what risk level to assign. This clearly links impact analysis to the question of how much regression testing is needed rather than tool selection or exit criteria definition.

Why Other Options Are Wrong:
Option A is wrong because writing new test cases for initial functional testing is more related to requirement coverage than impact analysis of changes.
Option C is wrong because selecting automation tools is a strategic decision and not the primary purpose of impact analysis.
Option D is wrong because exit criteria are part of the overall test plan and quality goals, not directly determined by impact analysis of a specific change.

Common Pitfalls:
Many learners confuse impact analysis with general test planning or risk analysis. While related, impact analysis specifically focuses on the consequences of modifying one part of the system on other parts. Another pitfall is to think impact analysis is only a development task and not tightly linked to regression testing. In practice, effective impact analysis is essential to optimize regression testing effort and to avoid both under testing and over testing after changes.

Final Answer:
How much regression testing should be done after a change is introduced