Risk based testing prioritizes test efforts based on risk scores to find critical defects earlier. It aims to test high-risk areas first, then medium-risk, and finally low-risk areas. Risk is defined as the probability of a fault occurring multiplied by the damage caused. Probability and damage are determined based on factors like complexity, usage frequency, and business criticality. The goal is to reach an acceptable level of risk where quality is good enough.

1. RISK BASED TESTING

2. TESTING because …

3. RISK BASED TESTING
– Why RBT ?
• Not finding critical defects until late in the development cycle
• Unsure of how much testing any particular application needs
• Testing effort is limited by time and money available
• You must be able to cut down on the least important things
• Complements Agile projects and feature scoring
• To bring the right level of consistency and business input to prioritizing
test efforts
– What is RBT?
• Prioritisation of test effort based on risk scores
• high-risk areas are tested first, then medium-risk and, finally, low-
risk areas.
• “The goal is to reach an acceptable level of risk. At that point,
quality is automatically good enough”

4. What is RISK ?
• Risk = You don’t know what will happen but you do
know the probabilities
• Uncertainty = You don’t even know the probabilities.
RISK
Damage
Probability of
failure
Lack of quality
Usage
frequency

5. • Risk = Probability of fault occurring X Damage caused by fault
• Damage determined by -
financial, loss of clients, corporate identity, usage frequency
• Probability determined by -
complexity, size, prior knowledge, experiences gained
during testing (defects tend to clump together), newly
developed product vs. “off-the-shelf”
RISK BASED TESTING

6. risk
identification
•risk workshops
•expert interviews
•heuristics
•lessons learned
•checklists
Project Mitigation
Test
Contingency plan
Ignorerisk
analysis
risk
mitigation
(control)
risk
monitoring
• potential severity
of impact
• the probability of
occurrence
• prioritize the
implementation

7. Probability of Failure
Changed Areas
Complexity
Defect Proned Areas
Impact of Failure
Usage frequency
Visible areas
Business Criticality
• can be hard to commit to…
• can help answer - how much testing is enough
• is a risky business in itself and does not mean test all known risks
RISK BASED TESTING
The main initiative being…
to provide detailed information to help ‘management’ make a
decision on whether a system is ready for release