In order to correctly reflect the full cost of your actual and planned headcount that you are forecasting in Jirav you will need to create OpEX drivers.
Generally there are two primary methods, you can apply an assumption of a percentage of the salary or you can break out the expense granularly between taxes and benefits; this example will show both methods.
By taking a percentage of the total salary expense is the simplest and most straightforward way to forecast in Jirav; though it may not be the most accurate.
This is completed by going to Plans->Drivers and creating an OpEx Driver that is based off the total Salary Dollars and multiplying this by 20%, assuming that 20% is the average amount of the fully burdened amount.
As you can see in the screen shot below we have a calculation of 20% of the total salaries being output into the employee burden expense account.
To be a bit more granular we will break out the tax rate (Federal + State/local) and the employee benefits. For the tax we will assume a federal rate of 7.65% (Social Security + Medicare) and 10% for State+Local taxes for a total of 17.65%. For the benefits cost we will assume $450 per headcount.
Based on this we will create two OpEx drivers, one for the tax rate and a second for the benefits cost. Note that the output for each of the drivers is now explicitly "Benefits" and "Taxes" as well as the driver for the benefits is based on the headcount number and not the dollars since we are multiplying the value by the dollar amount within the rate column.