Defense acquisition policies require that program managers conduct technology readiness assessments for all critical technologies. Technology Readiness Levels (TRLs) are frequently used in performing these assessments. While there is considerable evidence to support the utility of using TRLs in assessing program risk, there are some difficulties in using TRLs with software. This report explores these problems as they apply to non-developmental item (NDI) software technology and products, including commercial off-the-shelf, government off-the-shelf, and open source software. The problems take four principal forms:
1. TRLs "blur" several aspects of technology and product readiness into a single number.
2. TRLs do not account for the criticality of a product or technology to the system as a whole.
3. TRLs don't account for software technology and product aging.
4. TRLs do not provide any means to deal with how the relative contributions of the various aspects of readiness vary throughout the life cycle of a system.
This report examines these issues in detail and proposes an alternative approach for determining product readiness of NDI software technology.