Software Process Improvement or SPI, is the creation and adoption of a set of standardised processes that make sure that projects are delivered as expected.  The surprising thing about SPI is that it is mostly a business system rather than a technical system.  Understanding what is important to plan, monitor and complete, rather than how to carry out the technical specifics is the important thing.  Adherence to a software methodology doesn't require a specific kind of technology to be used, or a specific technical skill set.

In the same vein, the benefits from SPI are improved business outcomes, not abstracted technical detail. 

A sample Software Methodology can be viewed here.