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What is a Software Bug?
A software bug is a problem that causes a program to crash or produce invalid output. It is usually caused by insufficient or erroneous logic. A bug can be an error, mistake, defect, or fault that may cause failure or a deviation from expected results.
Most software bugs are due to human error in a program’s source code or design. Software is said to be buggy when it contains a large number of bugs, which affect program functionality and cause incorrect results.
Some bugs might not have serious effects on the functionality of the program and may remain undetected for a long time. When serious bugs are left unidentified, a program might crash. Another category of bugs, called security bugs, may allow a malicious user bypass access controls and obtain unauthorized user privileges.
Key Takeaways
- Software bugs can cause programs to malfunction, slow down, or fail to start.
- They’re mainly caused by human error and mistakes in the development process.
- Their impact ranges from trivial to severe, with serious implications for medical, transport, and other sensitive industries.
- With effective processes in place, most bugs can be identified and fixed.
- Finding and fixing bugs is now seen as a standard practice in software development.
History of Software Bugs
Some of the worst software bugs in history include:
- In 1962, a bug in the flight software of the Mariner I spacecraft caused it to divert from its expected path.
- In 1982, bugs in the code controlling a medical device called Therac-25, used for radiation therapy, led to patient deaths.
- In 1990, a bug was found in the new release of AT&T’s software control #4ESS long-distance switches caused many computers to crash.
- In 1996, the Ariane 5 rocket was destroyed a few seconds after launch due to a bug in the onboard guidance computer program.
What Causes Software Bugs?
The root cause of almost all software bugs is human error. However experts have identified flaws in the software development and testing process that can lead to more – or more serious – errors occurring.
These include:
- Weak collaboration: If exact requirements are not communicated correctly to the software development team, it may cause software defects.
- Inappropriate testing frameworks: Using the wrong testing framework in an automated testing environment can cause some defects to go undetected.
- Poor defect management processes: If quality assurance testers don’t have an effective and standardized process for defect discovery and removal, software bugs can slip through.
Types of Software Bugs
Impact of Bugs on Software Development
In today’s digital world, software bugs can have a serious impact, putting lives at risk in healthcare settings or causing serious disruption to essential systems in finance, transportation or other critical infrastructure. Bugs can degrade software performance, reduce its reliability, or make it unusable for certain tasks.
They also increase the cost, time, and resources required for software development and patch management. Brand reputation and trust can also be hurt, exposing the software development firm to legal liabilities or creating security vulnerabilities.
How to Prevent Software Bugs
Development teams need open and transparent communication, where everyone is encouraged to discuss issues or conflicts with a program’s specifications.
BDD is a software methodology that aims to simplify development by converting natural language into executable tests.
Encourage developers to separate code into distinct concerns, with more frequent code reviews to reduce the frequency of bugs.
Expand the code review process to include more people, with several developers reviewing all or specific sections of code.
Best Practices to Resolve Software Bugs
Software Bug Examples
Example 1
An inventory management system program appears to be error-free but doesn’t respond.
After a thorough evaluation, testers discover that a single parenthesis is missing from one line of code, which is enough to stop the program from executing further operations.
Developers call this a syntax error.
Example 2
A developer creates two different files, each containing different sections of software code. While one file is imported into the other, the software program code crashes or the file import fails to execute.
Developers call this a system-level integration bug.
The Bottom Line
Software bugs are part of the development process making debugging an essential aspect of quality assurance (QA).
Human error is a fact of life in software development and everything from simple typos to miscalculations in advanced logic can cause bugs to occur. With rigorous princesses and the latest testing tools, development teams can catch and repair the vast majority of bugs before a new piece of software is released to the market.
FAQs
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References
- Mariner I Space Problem Failure: First of the “Ten Greatest Software Bugs of All Time” : History of Information (Historyofinformation)
- Therac-25 – Ethics Unwrapped (Ethicsunwrapped.utexas)
- The Crash of the AT&T Network in 1990 (Telephoneworld)
- The Worst Computer Bugs in History: The Ariane 5 Disaster | BugSnag Blog (Bugsnag)
