You can make Expected revenue a functional field which contain total of all there fields or you can make onchange method on all there fields on change transfer total value to the Expected revenue field

def expexted_revenue(self, cr, uid, ids, field_name, arg, context=None):
            res = {'planned_revenue': 0.0}
            for line in self.browse(cr, uid, ids, context=context):
                res[line.id]['planned_revenue'] = line.license + line.support + line.development
            return res