In ISTQB foundation level syllabus test analysis and design were considered together.
In ISTQB advanced syllabus test analysis and design are considered separate activities even though they can be implemented parallel, integrated or iterative to facilitate the production to test design work products.
Test analysis is an activity which defines “WHAT” need to be tested in the form of test condition. Test conditions are identified by analyzing the test basis, test objectives and product risks. Test condition should be traceable backward to test basis and forward to other test work products like test cases.
You can start test analysis for a particular test level as soon as the basis for testing is established for that test level. The level of details to include in the test conditions depends in various factors which are as follows: