## 3 Design and Construction Method Based on a Study of User Needs and the Operational System
In this step, the researcher puts him or herself in the place of the end-user, and employs tools such as empathy maps, ethnographic interviews, user observations, reconnaissance surveys with a thorough analysis of the environment and needs in the context of functionality. In order to define a design problem that pertains to the user's unconscious needs and to increase the probability of developing a new product or its new functionality, it is necessary to link empathy research with the research of the operational system. This relation is presented in Figure 6, which describes the tools for both stages of Explore (study of operating system) and Empathize. The following tools can be used to test the studied structure or product, as shown in Figure 6: infrared camera, high-speed camera, sensors, such as accelerometers, strain gauges, or numerical methods such as Computer Aided Design using Finite Element Method (CAD/FEM), Computational Fluid Dynamics (CFD) as well as Virtual Reality (VR) or Augmented Reality (AR). This kind of link between the in-depth study of user needs and the analysis of operational system is a new contribution to the proper definition of the design problem or design requirement. The connection of the in-depth user study with the results of research on the operational system of the whole machine (environment, work modes, service) guarantees the identification of the problem and thereby the design of a solution that is easy to implement and distinguishes the proposed method from the existing models. The effects of the implementation of these stages of correlated research have been validated by a number of studies carried out by the author [2; 4; 23; 24]. Tests on a demolition robot produced by one of the leading manufactures revealed that the needs are closely related to how the machine is controlled. The needs varied depending on whether the machine operator was seated in the operator's cabin on the machine or was controlling the machine remotely. When analyzing heavy machinery it is crucial to recognize the hidden and intuitive motivations that may affect human choices and behaviors. This process is the empathize stage and consists in the study of user needs. It begins with the collection of requirements by means of ethnographic interviews, user observations, or site visits. In the case of the studied remote-controlled demolition robot, in-depth interviews were conducted with 60 users. By analyzing the type of the user, it was possible to define two important types of personas, namely the operator and the chief or owner of the machine. For both groups, special interview questionnaires were prepared with approximately 15 questions to gather the hidden user needs in the context of functionality. The questionnaire asked questions concerning the use of the demolition robot in typical situations or during incidents. For instance, operators were asked what they disliked about operating this particular machine or how they thought equipment affected the quality of their work. Among others, the users complained about poor stability, problems with steering, faulty tracks, or problems with the hammer being stuck in the material being demolished. The in-depth interviews with users resulted in empathy maps for each persona, defined as a collaborative visualization of what we know about a particular type of user [18; 19; 20; 24]. The user research in combination with the analysis of the robot operational system, both of which were performed in accordance with the proposed method, provided a set of undefined and hidden needs that not only concerned the user but were also related to the operational system (use, service, and environment). One of the most important needs identified during the study was for the robot to provide information about its operating mode since the lack of such information could lead to machine failure, structure cracking, or machine overturning if an incorrect mode were engaged. The next stage of the design phase consists in defining the problem (DEFINE).