Students need to develop meta-reflection to strengthen their learning process and to be able to manage the continuous changes encountered in both higher education and workplaces. Reflection is the most important skill for achieving progress in work-integrated learning. For students to develop metareflection and achieve progression in their work-integrated learning, they need a systematic structure and tools they use consciously. The portfolio method could be one of those tools. In the present article, we discuss, from a theoretical standpoint, how teachers can develop a better structure for students so that students can strengthen their learning process and progression in their work-integrated learning in higher education during work placements, which in turn will promote lifelong learning. This progression in work-integrated learning will be discussed in relation to the "WIL4U" model together with examples of reflection questions, learning outcomes, learning activities and examination forms. The "WIL4U" model was developed from the "AIL 4E (DUCATION)" model created by Bernhardsson, Gellerstedt and Svensson. The purpose of the present conceptual discussion article is to highlight the portfolio method as a structure and tool for progress in work-integrated learning through reflection. With support of the portfolio method, students can develop their ability to make well-balanced, conscious and reflected choices in planning actions for work-integrated learning. This requires well-developed self-2 regulation and the ability to engage in meta-cognition and systematic meta-reflection to evaluate the effects of various actions. The portfolio method can also improve the reflection process and develop students' ability to self-learn, emphasize strengths and increase their ability to achieve learning outcomes in higher education.