Module 3 Assessment

Technique: Decision table testing as primary, with BVA for balance tier boundaries.

The three conditions create: 3 x 3 x 3 = 27 rule combinations in the decision table. Add BVA tests for tier boundaries: $0, $9,999, $10,000, $10,001, $49,999, $50,000, $50,001.

Estimated test cases: 27 (decision table) + ~14 (BVA, 2 per boundary x 4 boundaries x ~2 account types) = ~41 test cases. Can reduce with risk-based prioritization.

Primary: State transition testing. The elevator has clear states and events.

Emergency stop tests:

1. Emergency during upward movement → immediate stop, doors stay closed
2. Emergency during downward movement → immediate stop
3. Emergency while doors are open → doors stay open, movement locked
4. Emergency while idle → system enters emergency mode
5. Reset after emergency → system returns to idle on current floor
6. Emergency pressed twice → no additional effect
7. Emergency during door close → doors reopen + emergency mode
8. Power failure during emergency → backup power activates

Also test invalid transitions: pressing floor buttons during emergency (should be ignored).

1. Analyze uncovered code — identify which fraud detection and retry logic paths are not exercised
2. Determine if uncovered code is legitimate — is it dead code, error handling, or missed specification?
3. Add targeted white-box tests — specifically for fraud detection scenarios (high-risk transaction, velocity checks, geographic anomalies)
4. Add retry logic tests — network timeout → retry → success; retry → failure → final failure; max retries exceeded
5. Apply error guessing for common payment edge cases
6. Measure again — target 85%+ statement and 75%+ decision coverage
7. Consider mutation testing on critical payment calculations to validate test effectiveness

All-combinations: 2 x 3 x 4 x 5 x 2 = 240 test cases.

Pairwise: ~20-25 test cases (use a tool to optimize).

Tool: PICT (Microsoft’s Pairwise Independent Combinatorial Testing tool).

PICT model:

OS: iOS, Android
Screen: Small, Medium, Large
Network: WiFi, 4G, 5G, Offline
Language: EN, ES, FR, DE, JA
Theme: Light, Dark

Pairwise reduces 240 combinations to ~20 while guaranteeing every pair of values is tested.

MC/DC (Modified Condition/Decision Coverage) is required for safety-critical medical devices.

Reason: Medical device software falls under IEC 62304 and FDA guidance. For the highest risk class (Class C), MC/DC ensures each condition (patient ID, dosage, drug interaction) independently affects the dispensing decision. This is critical because a missed condition check could harm or kill a patient.

For the decision patientVerified AND dosageInRange AND noInteractions:

• MC/DC requires 4 test cases (N+1 = 3+1)
• Each test proves one condition independently determines the outcome
• Also add BVA for dosage boundaries (safe range edges)

Part A (10 points):

• Correctly maps at least 5 aspects to techniques (3 pts)
• Provides clear justification for each choice (4 pts)
• Identifies need for combining techniques (3 pts)

Part B (10 points):

• All relevant conditions identified (3 pts)
• Complete truth table with all rule combinations (4 pts)
• Correct actions for each combination (3 pts)

Part C (10 points):

• All states identified (2 pts)
• All transitions with correct events/guards (4 pts)
• Invalid transitions identified (2 pts)
• Sniping extension modeled correctly (2 pts)

Part D (10 points):

• Bid increment boundaries correct (4 pts)
• Sniping timing boundaries correct (3 pts)
• Edge cases identified (3 pts)

Part A: Technique Selection

Part B: Decision Table

Conditions: Auction active? | User != Owner? | Under bid limit? | Bid >= min increment? | Reserve met?

Part C: State Transitions

States: Draft → Active → Extended → Ended → Sold/Unsold

Key transitions:

• Draft → Active [seller publishes, start time reached]
• Active → Extended [bid in final 30s, +2min]
• Extended → Extended [another bid in final 30s]
• Active → Ended [time expires, no last-second bids]
• Extended → Ended [extended time expires]
• Ended → Sold [final bid >= reserve]
• Ended → Unsold [final bid < reserve OR no bids]
• Active → Sold [buy-it-now accepted]

Part D: BVA Test Cases

Bid increment (current price = $20, 5% = $1.00, minimum $1):

• Bid $20.99 → reject (increment < $1.00)
• Bid $21.00 → accept (increment = $1.00 = 5%)
• Bid $21.01 → accept

Current price = $10, 5% = $0.50, minimum $1:

• Bid $10.50 → reject (increment $0.50 < $1.00 minimum)
• Bid $10.99 → reject
• Bid $11.00 → accept (increment $1.00 = minimum)

Sniping protection:

• Bid at 31 seconds before end → no extension
• Bid at 30 seconds before end → 2-minute extension
• Bid at 29 seconds before end → 2-minute extension
• Bid at 1 second before end → 2-minute extension
• Bid at exactly end time → reject (auction ended)
• Bid during extension at 31s before new end → no further extension
• Bid during extension at 30s before new end → another extension