A rider board is an accessory to strollers, it is a platform attached behind the stroller allowing the older sibling to ride along even if the stroller is a single seated stroller. It is a convenient product to buy if the user does not want to buy a two-seated stroller but still needs to sometimes transport both children. This thesis is about developing a sit-on function for the rider board, allowing children to both sit and stand while riding along. The product will be developed to get a deeper understanding of what it is important to consider when integrating a new component into an already existing product. The research will analyze the existing and new requirements, focus on a smart integration between the new component and the product, match the existing product aesthetically and complete the specified tests. 

The development project follows the product development process and the front-end process to develop a sit-on function for a rider board. The process consists of methods that gather information from the users, competitors and about the product. Other methods that are included in the process are identifying customer needs, establishing target specifications, generating product concepts, selecting product concepts and testing product concepts. 

The final result includes a sit-on function with an integrated attachment function within the seat. The sit-on function is a newly developed component that is attached to the already existing rider board platform. The solution makes it easy for the user to attach and detach the sit-on function on the platform. The platform has some minimal design changes. The final concept is presented with a physical and virtual prototype has been tested and evaluated based on the standards and the requirements.