pISSN 2234-3806eISSN 2234-3814
Table. 2.
Comparison of FMEA between DI-60 and manual counting for WBC differentials (N=40)
| Process step | Potential defect | Potential intervention | Consequence | FMEA | ||||
|---|---|---|---|---|---|---|---|---|
| S | O | D | RPN | |||||
| DI-60 analysis | 1. Insert a slide in the instrument | Wrong slide or mechanical error | Repeat | Delay | 4 | 3 | 1 | 12 |
| 2. Scan ideal zone under low power (10 ×) | Mechanical error or poor image | Repeat | Delay | 3 | 2 | 1 | 6 | |
| 3. Acquire images under high power (100 ×) (pre-classification) | Mechanical error | Repeat | Delay | 4 | 1 | 1 | 4 | |
| 4. Verify results | Incorrect verification | Correct | WR | 6 | 2 | 4 | 48 | |
| Total | - | - | - | 70 | ||||
| Manual counting | 1. Place a slide on the microscope stage | Wrong slide or incorrectly labeled slide | Repeat | Delay, WR | 9 | 1 | 6 | 54 |
| 2. Scan ideal zone under low power (100 ×) | Low quality of slide or broken slide | Re-prepare | Delay | 6 | 2 | 1 | 12 | |
| 3. Count cells under high power (1,000 ×) | Incorrect counting | Repeat | Delay, WR | 9 | 2 | 8 | 144 | |
| 4. Record results | Clerical error | Correct | WR | 10 | 2 | 7 | 140 | |
| Total | - | - | - | 350 |
||||
The RPN scores based on four groups were not calculated due to no difference in the process step.
*According to the CLSI guidelines H20-A2, the manual count was calculated as the mean of the results of two experts. The definite RPN of manual counting was 700 (350×2); we compared only the analytical process between DI-60 and manual counting.
Abbreviations: FMEA, failure mode and effect analysis; WBC, white blood cell; N, number; S, severity; O, occurrence; D, detectability; RPN, risk priority number; WR, wrong result.
Ann Lab Med 2022;42:398~405 https://doi.org/10.3343/alm.2022.42.4.398
© Ann Lab Med