Calculating ROI equalizing point in time

Hi thschr,

As far as I know, I'm afraid we can't achieve that by DAX. I would suggest you try the R. Please check out the demo in the attachment.

dataset <- dataset[with(dataset, order(Index)),]
j <- 1
middle_value <- 0
new_col <- c()
nrows_dataset <- nrow(dataset)
for (i in c(1: nrows_dataset)) {
    if (middle_value == 0) {
        middle_value <- dataset$Cost[i] - dataset$"Net Revenue"[j]
        j <- j + 1
    }
    else {
        middle_value <- dataset$Cost[i] + middle_value
    }
    while(middle_value > 0 && j <= nrows_dataset) {
        middle_value <- middle_value - dataset$"Net Revenue"[j]
        j <- j + 1
    }
    if (middle_value <= 0) {
        new_col[i] <- as.character(dataset$Month[j - 1])
    }
    else {
        new_col[i] <- "null"
    }
}
result <- cbind(dataset, new_col)

Best Regards,

Dale