It may be more cost-effective to have the payroll programs written to exact specifications than to try to modify off-the-shelf programs to do something they were never intended to do.

• 约请专人编写合乎确切要求的工资单程序所花的费用，就可能会比通过修改现行程序，而使它能胜任过去未做过的事，要更便宜一些。