In system engineering context, a functional analysis is the systematic process of identifying, describing and correlating the functions a system must perform in order to be successful at any foreseen life-cycle phase or operational state/mode. By focusing on what the system must do disregarding the implementation, the functional analysis supports an unbiased system requirement allocation analysis. The system function architecture is defined in terms of process, protection (interlock) or nuclear safety functions. Then, the system functions are analyzed from several points of view in order to highlight the various pieces of information defining the way the system is designed to accomplish its mission as defined in the system requirement documents. The process functional flow is identified and represented by Functional Flow Block Diagrams (FFBD) while the system function interfaces are identified and represented by IDEFÿ diagrams. Function interfaces are defined as relationships across identified functions in terms of function input (from other functions or requirements), output (added value or outcome of the function), controls (from other functions or systems) and mechanisms necessary to fulfill the function. The function architecture is further detailed by considering for each function: a) the phase of application, b) the actions performed c) the controlled variable and control actions to be foreseen in the implementation of the functions, d) the system involved in the control action, e) the equipment involved in the function, f) the requirements allocated to the function. The methodology here presented are suggested for the designing of fusion facilities and reactors already from the first phases of the pre-conceptual design, as it is now for DEMO.
All Science Journal Classification (ASJC) codes
- Nuclear Energy and Engineering
- Materials Science(all)
- Civil and Structural Engineering
- Mechanical Engineering