The RKEM latency is calculated for each and every site found in COMS [RKEM Current Moves] table. The valid latency value is set as the median of values in the dataset.
Example: Calculating RKEM Latency across a set of RKEM moves for a site Using the below move data, the median of the calculated as (30 + 20) / 2 = 25 min, which is applied in the stock projection cut-off formulas. ACTDAT, CHDAT Latency |
Calculating the latency requires some fine-tuning of the implementation, to handle relevant exception cases. The known exception cases are described below.
| Case | Description |
|---|---|
| Time Zone | To calculate the latency of the individual moves, ROCK database has to use timezone data to transpose and compare the relevant values in the RKEM move (ACTDAT=local time, CHDAT=GMT, DCDAT=GMT) If no time zone data can be deducted, 24 hours used as fallback. |
| Inactive Site | If no Load move found for a site in COMS RKEM Current Moves table, then 24 hours used as fallback |
| High Latency | If the median for a site calculated is greater than 24 hours, 24 hours used as fallback |
| Slightly Negative Median | If the median latency calculated for the port is negative and less than 1 hour, then 60 minutes (1 hour) is added to the median value and used as cut off time for the port. (e.g. -40 min becomes -40 min + 60 min = 20 min). The assumption is that in these cases it discrepancy is due to daylight saving changes and ROCK lacks this data. |
| Negative Median | If the median latency is calculated as negative number but less than -1 hour, then no interpretation is applied, and 24 hours is used as a fallback. |
| Data captured before activity date | If the equipment moves have been inserted in RKEM (data capture date) before the equipment move happened (activity date), we disregard it. |