This thesis presents the research and development of a framework for creating design guidelines, aimed towards product-producing companies as a part of a brand extension strategy. The thesis answers two research questions:

RQ1: What strategies could be used to analyze visual form and product design as a part of a brand extension strategy for a product-producing company?

RQ2: How can an existing visual brand identity be utilized during the product development process and redefined for new product categories?

The thesis is divided into a literature review and a case application of the presented theories on a real-world product development process. The literature review includes three central frameworks. Firstly, a theoretical framework including theories regarding brand management, product design and form, design syntactics and product architecture is introduced. The theoretical framework also includes product modularity which is specifically included for the case application. These theories are used to create a form analysis framework, which is the second element of the literature review. The third element of the literature review is a framework for how to create design guidelines, based on explicit and implicit design features. The design guideline framework is built from insights and theories found in literature used throughout the literature review.

The case application focuses on the development of a new concept and design guidelines for a modular Autonomous Mobile Robot (AMR) for a case company. The case application utilizes the created theoretical frameworks for a real-world product development process. The created concept envisions the visual brand language of the case company, while also serving as the foundation for the design guideline development.

The form analysis framework is used to understand product design and form on already existing products within a product category. A total of six analyses are introduced, all with their own respective focus on different fields of study and area of application. The form analysis framework investigates three areas of application: Internal and external factors as well as the existing product family of a company. Applying the form analysis framework to the case show that these methods are suitable for analyzing the visual form of products.

By examining the internal factors of the case company, such as analyzing existing products and prior design guidelines, a format for key design principles can be created. Based on these design principles and insights from the form analysis, the visual brand identity can be transferred to a new product category and described through redefined design guidelines. Findings show that certain design features, such as color and usage of logotype, are the most suitable for acting as identity carriers. Utilizing these can bring cohesiveness to a product portfolio. It can be concluded that the use of explicit and implicit design features is a viable way to holistically describe and articulate product design.