Understand the importance of developing robust software and methods of…

The idea

Robust software continues to work correctly under unexpected input, heavy load or partial failure, and resists attack. It matters because failures can lose data, expose personal information, break safety-critical systems and damage trust. Two methods help identify vulnerabilities before they cause harm. Audit trails record who did what and when, so unusual access or changes can be traced and investigated. Code reviews involve other developers reading code line by line to find errors, insecure patterns and logic flaws that testing may miss. Together they support early detection, accountability and improvement.

For example: A review might spot a missing input check, while an audit trail could reveal an unauthorised login attempt.

What earns the marks

• Robust software continues to function correctly under unexpected input, high load or partial failure, and resists attack.
• Importance: prevents data loss, protects personal data, maintains safety and reliability, and preserves user trust.
• Audit trails record activity such as logins and file changes, providing accountability and evidence for investigating incidents.
• Code reviews involve developers examining each other's code to find errors, insecure patterns and logic flaws before release.

Common mistakes and how to put them right

• Thinking robust software means it never fails.

  Put it right: It means it handles failure gracefully and continues to operate safely or recovers.

• Confusing audit trails with backups.

  Put it right: Audit trails record activity for accountability, whereas backups copy data for restoration.

• Believing code reviews are only for finding syntax errors.

  Put it right: They also uncover security weaknesses, poor design and logic flaws.

• Assuming testing alone guarantees security.

  Put it right: Testing checks known cases, while reviews and audit trails can reveal unknown or insider threats.

Exam tips

• Link each method to a specific benefit, for example audit trails to accountability and code reviews to early detection of flaws.
• Use a concrete example such as a review finding a missing input validation check or an audit trail showing an unauthorised login.
• When explaining importance, refer to consequences such as data loss, financial cost, legal penalties and reputational damage.