Quality Assurance is an Architect's job...too.

One of the key responsibility of the Solution Architect is to ensure that quality software gets developed and delivered during the project lifecycle. This demands to be actively engaged in each phase of the project including quality assurance phase. I found following principles handy to ensure effectiveness of the testing cycle from the book "Practical Software Testing: A Process-Oriented Approach " by Ilene Burnstein.

Principle 1. Testing is the process of exercising a software component using a selected set of test cases, with the intent of (i) revealing defects, and (ii) evaluating quality.
Principle 2. When the test objective is to detect defects, then a good test case is one that has a high probability of revealing a yet-undetected defect(s).
Principle 3. Test results should be inspected meticulously.
Principle 4. A test case must contain the expected output or result.
Principle 5. Test cases should be developed for both valid and invalid input conditions.
Principle 6. The probability of the existence of additional defects in a software component is proportional to the number of defects already detected in that component.
Principle 7. Testing should be carried out by a group that is independent of the development group.
Principle 8. Tests must be repeatable and reusable.
Principle 9. Testing should be planned.
Principle 10. Testing activities should be integrated into the software life cycle.
Principle 11. Testing is a creative and challenging task.

Keeping these principles in mind, an Architect can help the testing team in determining the right set of test cases to excercise the components to the fullest and by introducing mechanisms for test automation to improve the testability of the software.