Navigate to KPIs on the Menu and click Add.
Then select the Measurement Type as Weighted Averages(Highlighted Red), you will then be presented with a field to select the KPI to link. that would be used as the Weight (by Clicking on the Link KPI button Highlighted Green).
A Weighted KPI can be used to achieve the following:
I.e Calculating a Head grade KPI (measured in grams of metal per tonne of ore), where:
The daily value is = (grams metal contained for the day)/(tonnes mined for the day); and
The weekly value is = (grams metal contained for the week)/(tonnes mined for the week); and
The monthly value is = (grams metal contained for the month)/(tonnes mined for the month)
In some cases, the KPI will be uploaded as the daily head grade value, but we need the weekly and monthly values to be weighted by the daily tonnes mined (in Excel you’d use SUMPRODUCT(grade,tonnes_mined)/SUM(tonnes_mined) – which is where the reference to weighted averages comes from
Other key examples are recoveries (% metal recovered by the process) and any throughput/rate KPI (tonnes milled per hour, dig rate, etc.). These KPIs all need the correct weighted average values to be reported to match existing site reporting (which itself is important as otherwise we risk calculating the incorrect grade for the month and thus the incorrect value of tonnes mined when using the monthly values).
The calculation applied is SUM([KPI] * [WeightedKPI]) / SUM([WeightedKPI])