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Data Quality
Calculating the data quality score
Introduction
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Each RCA receives an annual overall Data Quality Score, as shown to the right. The purpose of the overall Score is to indicate the quality of available data in the asset system to support investment and decision-making processes, weighted by a level of importance. The overall Score result is out of a maximum of 100. It is derived from the RCA’s individual results for each metric that are applicable, and reported, on their data. It is a weighted score based on the level of importance of each metric. High importance metrics contribute the greatest, then moderate and low contribute the least. A score of 100 is achieved by having all metric results at the expected standard level. A weighted value is given to each metric based on the level of importance and grade achieved using the matrix in table 1 below. |
Table 1
| Importance | Grade 1 | Grade 2 | Grade 3 | |
| High | 10 | 5 | 1 | |
| Moderate | 5 | 3 | 1 | |
| Low | 3 | 2 | 1 |
These values are then totalled and divided by the maximum achievable (i.e. Grade 1 for all metrics).
Metrics that are subsets of the same indicator (e.g. CWAY2a and CWAY2b) each contribute an equal proportion of the maximum achievable based on their individual result grade. For example two subset metrics of a high importance indicator each contribute a maximum of 5 (10 / 2).
Metrics are excluded from the overall Score calculation if they:
- are not applicable to a specific network (i.e. report a result of NA), or
- are Information Only metrics.
Example calculation
| Metric | Importance | Achieved Grade** | Value (from Table 1) | Max Achievable Value |
| Metric 1 | High | 2 | 5 | 10 |
| Metric 2 | Low | 3 | 1 | 3 |
| Metric 3a* | High | 1 | 10 / 2 = 5 | 10 / 2 = 5 |
| Metric 3b* | High | 3 | 1 / 2 = .5 | 10 / 2 = 5 |
| Metric 4 | Moderate | 1 | 5 | 5 |
| Metric 5 | Low | 2 | 2 | 3 |
| Total | 18.5 | 31 |
* Metric 3a and 3b are subsets of the same indicator - the maximum achievable value is halved between the subset metrics.
** Achieved Grades are: 1 = At expected standard, 2 = Minor issues, 3 = Major issues
Score for this example is: (18.5 / 31) * 100 = 59.7
The reported score is the score rounded to the nearest whole number: = 60