flowchart TB; CREATE_BILL[Create bill]-->LOCKED{Is locked?}; LOCKED-->|TRUE|CREATE_APPROVAL_TASK[Accounting approval task]; LOCKED-->|FALSE|PRINTABLE; CREATE_APPROVAL_TASK-->ACCOUNTING_APPROVAL{Is ok?}; ACCOUNTING_APPROVAL-->|FALSE|ACCOUNTING_NOT_APPROVED[Inform OP]; ACCOUNTING_APPROVAL-->|TRUE|PRINTABLE; CREATE_BILL-->CREATE_CHECK_TASK[Invoice validation task]; CREATE_CHECK_TASK-->BILL_CHECK{Is correct?}; BILL_CHECK-->|TRUE|CHECK_PRICES{High discounts?}; CHECK_PRICES-->|FALSE|PRINTABLE; BILL_CHECK-->|FALSE|INFO_WRITER[Inform OP]; CHECK_PRICES-->|TRUE|CREATE_SALES_APPROVAL_TASK[Sales approval task]; CREATE_SALES_APPROVAL_TASK-->SALES_APPROVAL{Is ok?}; SALES_APPROVAL-->|TRUE|CHECK_PRICES_ESCALATED{Over limit?}; SALES_APPROVAL-->|FALSE|SALES_NOT_APPROVED[Inform OP]; CHECK_PRICES_ESCALATED-->|TRUE|CREATE_CFO_PRICE_APPROVAL[CFO approval task]; CHECK_PRICES_ESCALATED-->|FALSE|PRINTABLE; CREATE_CFO_PRICE_APPROVAL-->CFO_APPROVAL{Is ok?}; CFO_APPROVAL-->|TRUE|PRINTABLE[Mark printable]; CFO_APPROVAL-->|FALSE|CFO_NOT_APPROVED[Inform OP + Sales]; CLICK_PRINT[Click print]-->IS_APPROVED{Is approved}; IS_APPROVED-->|TRUE|PRINT[Print]; IS_APPROVED-->|FALSE|PRINT_ERROR[Show print error]; UPDATE_BILL[Update bill]-->CHECK_THREASHOLDS{Change above threshold}; CHECK_THREASHOLDS-->|TRUE|OPEN_TASKS[Update & re-open tasks];