A product set is a set of products that you should install, maintain, and migrate as a group. Everyone has at least one product set that includes z/OS®. The judicious grouping of your other system software products into product sets can help you avoid reinstalling software you have already installed, give you greater flexibility during migrations, control the amount of DASD used for system software, and make it easier to have different groups maintain different sets of products.

Well-chosen product sets let you treat most system software in a logical, modular way. When different images have different sets of requirements, you can use product sets as modular building blocks to make the entire needed set of software available on each image. Specific recommendations for placement of each product set's data sets are discussed in Recommended data set placement.