As a product owner defining a release template, I should be able to specify the offset (relative to the start of the release) that a phase begins in order to support concurrent and overlapping release phases. The Release details view allows me to add/edit phases to support concurrency.
I agree with Angela. We need the flexibility to show overlapping design, development and testing.
In an agile environment, it would be beneficial to be able create release templates that allow overlap of design, development and testing phases within a single release.