OpenJDK uses a system for deciding the priority of open bugs. It's based on the concepts of Impact, Likelihood and Workaround effort for an issue, and in levels ranging from High through Medium to Low.

• Impact meaning how badly it affects a customer, with high being system unusable / data loss etc.
• Likelihood meaning how likely a customer is to encounter the issue, with High meaning that it's a virtual certainty.
• Workaround meaning how easy it is to workaround the issue, with High meaning that it is virtually impossible to find a tractable workaround.

This means that there are 27 (3^3) combinations of these, mapping to the standard P1 through P5 issue priorities in the Java Bug System.

The mappings can be found here:
http://hirt.se/images/openjdk/ilw.png

This was reverse engineered from information in public OpenJDK Jira issues. If you find any errors, please update the source spreadsheet.