Today, the effectiveness of products is mainly influenced by interactions between user and product, which are described by the handling of a product by the human being. Reasons are not only in the increasing functionality of today´s products, but also in the complexity of human-machine-interactions. An extension of the system borders is required to consider a stronger integration of the needs and the capability of the human being in the development. In that respect, the technical system should include the human being (human being-product-system). In the past, it has turned out that it is not helpful to describe the human being only based on his capacities or, respectively, his performance restrictions. In fact, it is also necessary to consider his specific life situation and the action situation. Such an extended view connected with the integration of the human being in the system s contemplation assumes a holistic reflection of the human being. In addition, it demands novel methods to validate the products in their functionality concerning a holistic view of the human being. The focus of the paper lies on the last point. A model approach is explained which assess the usefulness of a product, based on a holistic view of the human being, will be explained. This approach is based on a specific interpretation of the concept of  barrier , which combines a product´s point of view with a user s point of view. As a result, a capacity-support-diagram is derived in which products are classified. This kind of representation helps to explain not only the use of a product, but also to implement a support hierarchy for the human being with products. This representation serves the purpose of deriving key aspects for the product development.    «

Today, the effectiveness of products is mainly influenced by interactions between user and product, which are described by the handling of a product by the human being. Reasons are not only in the increasing functionality of today´s products, but also in the complexity of human-machine-interactions. An extension of the system borders is required to consider a stronger integration of the needs and the capability of the human being in the development. In that respect, the technical system should i...    »