Day3_​S3_​ok

Stage 1 - Read and Shewhart

The criterion with no memory: one point over 3SD

Stage 1

1. Read the S2 residual file, 2,151 rows
2. Parse ts_hour
3. Family 1: |z| > 3 on vib and on temp
4. This is the criterion S2 already used

Stage 2 - Western Electric

The criterion with short memory: a run, not a single jump

Stage 2

1. Raw one sided flags at 2SD, 1SD and 0
2. Count them over 3, 5 and 8 points
3. 2 of 3 over 2SD, 4 of 5 over 1SD, 8 in a row
4. Three rules from six counters

Stage 3 - CUSUM

The criterion with cumulative memory, built without recursion

Stage 3

1. u = z - k with k = 0.5
2. Cumulative sum, then running minimum
3. S = C - Cmin, no recursion needed
4. Alarm at H = 10 for vib, H = 6 for temp

Stage 4 - Evaluate to the repair date

Cut the window at the repair, then roll up to days

Stage 4

1. Read the work orders for the truth
2. Keep the hours up to the repair date
3. Without this cut CUSUM looks far worse
4. 74 days, 22 of them with a real defect

Stage 5 - Scoreboard

One table, ten criteria, the same day unit as S2

Stage 5

1. Label every day TP / FP / FN / TN
2. Unpivot, then pivot to a 10 x 4 matrix
3. Empty cells become 0 before dividing
4. precision and recall for every criterion