Traditional design theories have focused on technical functions and more or less disregard a product’s user involvement. The existing methods of ergonomic designare mostly intended for analysis activities. There is a need for new dynamic methods that focus on user-product interactions. The aim of this research work is to develop design methods for user-product interactions, which should support synthesis activities in early product development phases.

An observation study and a questionnaire survey were carried out in order to investigate product developers’ work and relation to the users for providing background information about the research problem. Furthermore, student projects in product development were followed, giving essential input. After the theories and

methods were developed, a retrospective interview study was carried out in order to confirm the need for the developed methods. The studies showed, for instance, that companies use few formal methods and almost none of these are directed towards the user. It is also indicated that the product developers’ contact with users decreases with increasing company size. Few companies have a defined procedure for defining their intended users.

Six methods are developed. They embrace three ways of classifying the users and their relations to products and other users (User identification, Use profile and User relations), an analysis of the users’ Activities, goals and motives behind their use of the product, a scenario technique (User-technical process scenario, UTPS), which shows the user process in parallel with the technical process, and a hierarchical decomposition of technical functions and user actions, which is named the Functionaction tree (FAT).

All the methods, apart from FAT, were tested in real product development teams. All the tested methods stimulate communication between the group members of various competencies in the design group. Most of the methods are easy to apply and are valuable for understanding the design problem. The UTPS is also useful for comparing design solutions and generates new ideas about the design task. The other

tested methods did not generate many new ideas, but the reason is probably that they were mainly tested on products that are already on the market. Thus, the methods are most valuable in the early design stages, when trying out a product idea or a concept.