From development strategy to error detection criteria, a Test Plan outlines the steps that will be taken during testing. The document also specifies how to resolve detected risks.
Test Strategy is a set of instructions, guidelines, or principles determining how the tests will be designed and executed. It sets the testing process standards.
Main goal of test plan is to specify how, when, and who will test a product, while the primary objective of test strategy is to specify the principles to follow during testing.
The test plan identifies and mitigates potential inconsistencies in the final product, while the test strategy is a long-term plan of action for the testing process.
A test plan is a dynamic document that can be modified multiple times according to specifications of test, whereas a test strategy is a static document that cannot be altered.
Test plan includes test plan ID, features to be tested, test techniques, pass/fail criteria, etc., while test strategy includes objectives & scope, documentation, and test processes.
A testing manager or lead prepares a test plan highlighting how to test, when to test, and who will test. A test strategy is developed by the project manager as part of the testing process.