Estimate Expected Impact of a Defect
Estimating the expected impact of
a defect is a crucial part of the software testing process. It helps in
prioritizing the defects and in deciding the corrective action required. Here
are some factors that are considered while estimating the expected impact of a
defect:
- Severity of the Defect: This refers to the
degree of impact the defect has on the system's functionality. Severe
defects might cause the system to fail or crash, or could affect critical
functionalities. Lower severity defects might impact non-critical
functionalities or cause minor inconveniences.
- Frequency of Occurrence: How often the
defect occurs can also influence its impact. A defect that occurs
frequently can have a larger impact compared to a defect that occurs
rarely, even if the individual impact of each occurrence is low.
- User Impact: If the defect affects a feature
that is frequently used by many users, the overall user impact can be
high. If the defect only affects a few users or a feature that is rarely
used, the user impact may be lower.
- Business Impact: The impact on the business
operations and objectives is also considered. A defect that affects a
critical business process or objective can have a high impact.
- Data Impact: Defects that can lead to loss
of data or corruption of data can have a very high impact, given the
importance of data in any software system.
- Security Impact: Defects that expose
security vulnerabilities can have a very high impact, as they can
potentially lead to breaches and unauthorized access.
After considering these factors,
an expected impact can be estimated for the defect. This helps the team to
prioritize which defects to fix first and to allocate resources effectively.
Techniques for Finding Defects
There are several techniques for finding
defects in software systems. These techniques can be broadly categorized into
static and dynamic testing techniques:
- Static Testing Techniques:
- Reviews: This can be peer reviews,
walkthroughs, or formal inspections. Reviews are done on the documentation
including requirements, design documents, and source code.
- Static Analysis: This is usually carried out
by tools and includes techniques like data flow analysis, control flow
analysis, cyclomatic complexity measurement, etc. It helps to find issues
like unreachable code, syntax violations, memory leaks, etc.
- Dynamic Testing Techniques:
- Unit Testing: This is typically done by
developers. It involves testing individual modules or components of the
software to ensure they are working correctly.
- Integration Testing: This involves testing
the interaction between different modules of the software.
- System Testing: This is a high-level testing
where the entire system is tested to ensure it meets the specified
requirements.
- Acceptance Testing: This is usually the
final testing done before the software is released. It involves testing
the system in the real environment by the intended audience.
- Manual and Automated Testing:
- Manual Testing: This involves testers
manually executing test cases and observing the results.
- Automated Testing: This involves using
automated tools to execute test cases. Automated testing is typically used
for regression testing, performance testing, load testing, etc.
- Experience-based Techniques:
- Exploratory Testing: This involves testers
exploring the software based on their experience, knowledge and intuition.
- Error Guessing: Here the tester guesses the
most probable areas where defects can occur based on their past
experience.
Defect Clustering and Pareto
Analysis: In defect clustering, testing effort is concentrated on areas of
the software where defects are most likely to be clustered. Pareto analysis is
a statistical technique used in decision-making to identify a set of
priorities.
Choosing the appropriate technique
depends on several factors like the type and complexity of the software, the
development lifecycle, project timeline, and resources available.
Reporting a Defect
Reporting a defect is a crucial
part of the testing process. It involves detailing the defect in such a way
that developers can reproduce and fix it. To effectively report a defect, it's
essential to provide as much detail as possible.
Here are the steps involved in
reporting a defect:
- Identify Defect: During testing, if the
software doesn’t behave as expected, it may be due to a defect.
- Record Defect: As soon as you find a defect,
record it. It’s crucial to document the defect at the right time to avoid
forgetting any details.
- Defect Details: Include as much information
as possible. Here are some essential fields in a defect report:
- Defect ID: A unique identifier for the
defect.
- Title: A concise summary of the defect.
- Description: A detailed explanation of the
defect.
- Steps to Reproduce: Clear instructions on
how to reproduce the defect.
- Expected Result: What the system should do
if it were working correctly.
- Actual Result: What the system actually
does, which is causing the issue.
- Severity: The level of impact on the system
(Critical, High, Medium, Low).
- Priority: The order in which the defect
should be fixed (High, Medium, Low).
- Attachments: Screenshots, logs, or any
other files that support your findings.
- Submit Report: After documenting the defect,
submit the report using a bug tracking tool. This could be software like
Jira, Bugzilla, or any other tool your team uses.
- Re-testing & Closure: Once the developer
fixes the defect, re-test the functionality to ensure the problem has been
resolved. If it’s fixed, close the defect in the defect tracking tool. If
the defect still persists, reopen it and notify the development team.
Remember, the aim of a defect
report is to enable another person to reproduce the defect, understand what's
wrong, and ultimately fix it. Clear and complete reports make the process
smoother for everyone involved.