## 4 Conclusions  
A novel facility for testing the static and dynamic stability of agricultural machinery has been conceptualized and studied, and its layout has been designed by means of the design process described herein. The illustrated approach draws on the one normally used for the development of an industrial product but takes into account the differences pertinent to the specific case under consideration. Indeed, the design of a test apparatus is different from that of an industrial product because it is more focused on the technical characteristics that the test apparatus must be able to investigate. The effort of conceptualization is therefore greater because the conceptualization phase necessarily requires an extra step. Specifically, the whole design process originated from the necessity of a test rig to make vehicles experience situations as close as possible to real ones. The development of this system began from macro-requisites and reached the definition of the minimum technical requirements of each subsystem, gradually focusing on smaller and smaller parts and increasing the level of detail. Two principles demonstrated particular advantage in the design process: the functional analysis and functional decomposition, and the kinematic inversion. The outputs of this design process are several schemes and CAD-drawings concerning the system and the solutions to be adopted on it. These outputs can be used to guide the action of a designer involved in the detailed design of the system. From a practical point of view, the relevance of this study is demonstrated by the effectiveness and ease of application of the presented methodology. The acknowledged criteria that are part of it led to the development of an enhanced test rig configuration. The approach proposed here is a key to interpreting the needs of the several agents usually involved in a product-development process, especially when it involves players with different backgrounds. Indeed, the needs of the client should be interpreted as technical features and/or final requirements of the test facility to be developed. The client only sums up the technical requirements that a hypothetical test structure should be able to test, but without any idea on how this test structure should be developed. A structural engineer is then able to properly dimension a structure, yet does not necessarily have an idea about the final tasks that the product should perform and will require a set configuration of the test facility on which to work to define the final design and the construction details. Between client and structural engineer, an interface person filling the gap must be able to listen to the committers, interpret their needs [67], and translate them into technical requirements of a test structure for the engineer who can, at this point, play his role in the most effective way. This interface role can be guided by the procedure outlined in the present paper. Therefore, the methodology and its conceptual tools facilitated the development of the concept for a test rig, and served as a tool to ease the communication between the players involved in the product development, to overcome the barriers between those who identify the requirements, those who must develop the technical solutions and any other experts in the field. The proposed equipment is configured as a mechanical installation with three degrees of freedom: it presents a wide 'tiltable' plane with a central articulation hinge, specifically thought for performing dynamic tests (travelling of circular paths, possibly with a sharp change of the slope in the middle thanks to the articulation hinge) and operated by hydraulic jacks. An additional subsystem configured as a rotating platform ('turntable') can test the stability of motionless vehicles without the need for repositioning.