Calculator Inputs
Use period outputs, target data, and supporting quality signals to produce a weighted consistency index.
Example Data Table
| Period | Output Units | On Time | Defects | Comment |
|---|---|---|---|---|
| Week 1 | 92 | Yes | 3 | Minor ramp-up variation |
| Week 2 | 95 | Yes | 2 | Matched target closely |
| Week 3 | 91 | No | 4 | Delay caused lower throughput |
| Week 4 | 97 | Yes | 2 | Recovered after process fix |
| Week 5 | 94 | Yes | 1 | Stable and predictable |
| Week 6 | 96 | Yes | 1 | Strong finish |
Formula Used
Mean output: μ = Σx / n
Standard deviation: σ = √[Σ(x − μ)2 / n]
Coefficient of variation: CV = σ / μ
Stability score: 100 / (1 + CV)
Target score: 100 − |μ − Target| / Target × 100
Quality score: 100 − Defect Rate
Timeliness score: On-Time Rate
Coverage factor: (Planned Periods − Missed Periods) / Planned Periods
Output Consistency Index: OCI = Weighted Base Index × Coverage Factor
The calculator first measures spread using the coefficient of variation. Lower variation creates a higher stability score. It then blends stability, target fit, quality, and timeliness using your chosen weights. Finally, it applies the coverage factor so missed periods reduce the final consistency result.
How to Use This Calculator
- Enter your output numbers for each period in the series field.
- Add the target output that represents expected delivery per period.
- Enter defect rate and on-time completion rate for the same time window.
- Provide planned and missed periods to capture availability and coverage.
- Adjust the four weights if some dimensions matter more in your workflow.
- Click Calculate Index to display the result above the form, then export it as CSV or PDF.
Frequently Asked Questions
1. What does the Output Consistency Index measure?
It measures how reliably work output stays near target while preserving quality, timeliness, and coverage. A higher score means steadier, more dependable delivery across periods.
2. Why is coefficient of variation used?
Coefficient of variation scales standard deviation against the average. That makes spread easier to compare across teams, roles, or periods with different output volumes.
3. Can I use daily, weekly, or monthly data?
Yes. Use any period length you want, but keep all inputs aligned to the same cadence. Mixing daily output with monthly targets will distort the result.
4. What is a good OCI score?
Scores above 90 indicate exceptional consistency. Scores from 75 to 89 are strong. Scores from 60 to 74 suggest moderate control, while lower values show instability or coverage gaps.
5. Why does missing periods reduce the final score?
Missed periods reduce coverage. Even if active periods look stable, skipped work windows weaken overall dependability, so the coverage factor adjusts the final index downward.
6. Should the four weights total 100?
They do not have to total 100 because the calculator normalizes them automatically. Still, keeping them near 100 makes the intended priority mix easier to review.
7. Does exceeding the target always improve the score?
No. The target score rewards closeness to the target, not overshooting alone. Large positive or negative gaps both lower alignment because consistency values predictability.
8. What if quality matters more than speed?
Increase the quality weight and reduce other weights. That shifts the index so defect control influences the final score more strongly than throughput or timeliness.