Multiple Fault: Half-Split Failure Probs. (no refinement)
(no refinement)
What is the purpose of this algorithm?
The fault isolation algorithm Multiple Fault: Half-Split Failure Probs. (no refinement) is the same as the algorithm Multiple Fault: Half-Split Failure Probs. (refinement postponed) with the exception that refinement tests are omitted altogether from the generated diagnostic test sequence. This algorithm is a good one to use when trying to improve isolation for a design. One of the other algorithms can be used to determine how good the isolation is, whereas this one can be used to determine what tests to develop in order to improve isolation. Then, once those tests are defined, the Analyst can switch back to the other algorithm (which allows refinement) in order to evaluate the full benefit of the additional testing. The weightings for this algorithm favor tests that come close to half-splitting the suspect set when they pass or fail.
How was this algorithm implemented?
The full set of test selection criteria for this algorithm are as follows:
1. Test Candidate Grouping 1 of 2: Test Set Isolation
a) Candidate Test Types (1)
b) Weightings: uses algorithm defaults
c) Cutoffs: uses algorithm defaults
2. Test Candidate Grouping 2 of 2: Internal Isolation
a) Candidate Test Types (2)
2) All Input Flags
b) Weightings: uses algorithm defaults
c) Cutoffs: uses algorithm defaults
1. Test Weighting 1 of 6: Sum Failure Probability
a) Priority: 50
b) Entity: Failure Probability
c) Type: Sum
d) Domain: Suspect Functions Detected
e) Best Equals: Half-Split
2. Test Weighting 2 of 6: Sum Failure Probability
a) Priority: 50
b) Entity: Failure Probability
c) Type: Sum
d) Domain: Suspect Functions Proven
e) Best Equals: Half-Split
3. Test Weighting 3 of 6: Sum Failure Probability
a) Priority: 40
b) Entity: Failure Probability
c) Type: Sum
d) Domain: Suspect Failure Modes Detected
e) Best Equals: Half-Split
4. Test Weighting 4 of 6: Sum Failure Probability
a) Priority: 40
b) Entity: Failure Probability
c) Type: Sum
d) Domain: Suspect Failure Modes Proven
e) Best Equals: Half-Split
5. Test Weighting 5 of 6: Count Number of Items
a) Priority: 20
b) Entity: Number of Items
c) Type: Count
d) Domain: Suspect Functions Detected
e) Best Equals: Half-Split
6. Test Weighting 6 of 6: Count Number of Items
a) Priority: 20
b) Entity: Number of Items
c) Type: Count
d) Domain: Suspect Functions Proven
e) Best Equals: Half-Split
C. Default Test Cutoffs (2)
1. Cutoff 1 of 2: Count Number of Tests
a) Entity: Number of Tests
b) Type: Count
c) Domain: Isolation Path
d) Modifier: Test Usage
e) Target: Refinement
f) Condition: >= 3
g) Action: Ignore in Sequence
2. Cutoff 2 of 2: Count Number of Items
a) Entity: Number of Items
b) Type: Count
c) Domain: Suspected Items
d) Modifier: <none>
e) Target: <none>
f) Condition: <= 1
g) Action: Terminate Sequence
