After testers know their testing missions, they can create testing strategy. This post gives testing strategy definition that is aligned with Black Box Software Testing Foundations course (BBST) created by Rebecca Fiedler, Cem Kaner and James Bach.
So you have your testing missions.
Test strategy is answer to question how will you achieve your missions? Strategy is a set of ideas that guide your test design, logistics is set of ideas that guide your application of resources, and plan is combination of strategy, logistics and your project risk management.
Test strategy is based around IDEA. This concept confuses many development teams that think that testing is well known craft and anybody could do it. You just execute testing instructions written in test cases without using your brain.
But you know they are wrong. Humans are creative, and even on your first testing session where you followed instructions from test cases, you were hit with a number of ideas and questions about the product. A number of “What if” questions.
But you must also take into account your logistics. Resources are time, money, tools. What are your staff’s knowledge and skills? Do you know your project environment, what is easy, hard, cheap about it? And most importantly, what risks apply to your project. For more, go to Heuristics Test Strategy Model [Bach].