Monthly planned and actual nominal return are based on monthly planned and actual costs and benefits. The nominal return for any particular month is the difference between the benefit total for that month and the cost total for that month:
Nominal Return = Benefit – Cost
The Nominal Return and Total Nominal Return fields used in financial summaries and scenario comparisons are calculated from planned and actual costs and benefits over all the months that have any data. To determine total costs and total benefits over the entire time range, monthly contributions are based on values for each individual month, as follows:
For each previous month, actual cost is used wherever it has been reported, that is, wherever the value is not blank or zero, otherwise forecast cost is used. Similarly, actual benefit is used wherever it has been reported, otherwise forecast benefit is used.
For the current month, the higher of forecast and actual costs is used. Similarly, the higher of forecast and actual benefits is used.
For each future month, forecast costs and forecast benefits are used.
These monthly amounts are summed to determine total benefits and total costs, and total nominal return is the difference:
Total Nominal Return = Total Benefits – Total Costs