For many organizations the natural home for their core business applications is the mainframe. The original investment in that technology can date back 30 years or more, and the continued investment in maintenance, product updates, and support has to show a return year over year. That is why it makes sound fiscal–as well as business and technical–sense to ensure that the quality of your applications is optimized through robust testing procedures. However, on the mainframe, these can come at a cost. The purpose of this white paper is to examine the alternative approaches to testing mainframe applications and highlight the most cost-effective and pragmatic ways of addressing mainframe testing concerns.