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Managing System Models
Published in John P.T. Mo, Ronald C. Beckett, Engineering and Operations of System of Systems, 2018
Functional decomposition refers broadly to the process of breaking down a functional relationship into its constituent parts in such a way that the higher level function can be understood as a series of connected, simpler functions. This decomposition process is undertaken either for the purpose of gaining insight into the constituent components or to achieve a certain level of modularity. The basic idea is to try to divide a system, starting from the top “system level,” in such a way that each block of the block diagram can be described as a linked set of functions inheriting the same input, control, mechanism, and output of the higher level function. This top down modeling approach enables the complexity of a system to be unwrapped through a number of simple steps. At the start of the modeling work, we represent the whole system as one block. Next, we go into details to decompose the block into several linked sub-blocks. Each of the sub-blocks is further decomposed to the next level (Figure 15.1).
Enhancing innovation Methods, cultural aspects, ideation approaches, and box busters
Published in Adedeji B. Badiru, Cassie B. Barlow, Defense Innovation Handbook, 2018
Daniel D. Jensen, Cory A. Cooper
The idea of functional decomposition is to break a problem into descriptions of “what the solution to the problem needs to accomplish.” This helps maximize the quantity of ideas in the solution space. To do so, the descriptions of the problem must be related to WHAT the solution needs to do, not HOW it will do it [16].
Conceiving Design Solutions
Published in Bahram Nassersharif, Engineering Capstone Design, 2022
Functional decomposition is also a methodology used in systems design, where a system is decomposed into sub-systems, sub-sub-systems, and so on. At the end of each decomposition chain, a device or sub-system will be listed where a solution exists or is achievable.
Functional decomposition—A contribution to overcome the parameter space explosion during validation of highly automated driving
Published in Traffic Injury Prevention, 2019
Christian Amersbach, Hermann Winner
The approach of functional decomposition is broadly used in different domains (e.g., mathematics or informatics) to decompose complex problems, functions, or systems into less complex subproblems, -functions, or -systems. The authors suggest transferring this method to HAD functions and using it to generate particular test cases for the individual functional layers (i.e., subsystems) rather than testing the complete function in a system test. Therefore, the driving function is decomposed into functional layers that are tested individually and are evaluated on their interfaces. For this particular testing, evaluation criteria for each functional layer have to be derived from evaluation criteria or safety requirements on a system level. This can be achieved by applying fault tree analysis or similar methods. For example, the system-level fail criterion “(physically avoidable) collision with an obstacle” can be decomposed to minimum required object detection (functional layer 1), classification (layer 2), and prediction (layer 3) criteria as well as criteria for the planning (layer 4) and execution (layer 5) of a successful evasion or braking maneuver. The functional layers and the interfaces between them are based on the decomposition of the human driving task by Graab et al. (2008) and can be seen in Figure 2. The concept of particular testing is introduced in detail in (Amersbach and Winner 2017).
Towards a modelling framework for designing active check valves – a review of state-of-the-art
Published in International Journal of Fluid Power, 2018
Niels Christian Bender, Henrik Clemmensen Pedersen, Andreas Plöckinger, Bernd Winkler
A well proven approach to design hydraulic ACVs does not exist at the current state of research, nor have the significant wear mechanisms been identified. Therefore, a flowchart of the ACV design has been established as seen in Figure 1 inspired by Roemer et al. (2012). As seen in the figure, the modelling framework is what is of interest in this paper. A major task is here to evaluate the operating conditions (temperatures, local pressures, contact-impact speeds, loads, fluid flow, etc.) of an ACV applied in some arbitrary system, e.g. a DDM. To accomplish this, the design tool needs to include multiple physical phenomena such as fluid dynamics, structural mechanics and thermohydrodynamics. The review emphasises current state-of-the-art within each area, thus only focusing of main contributions. The objective is to give an overview of the design problem by functional decomposition, hereby highlighting the required modelling. The ACV design will among other factors be affected by wear. Studies of wear have shown that universal wear models are not yet identified (Hsu et al. 1997, Williams 1999, Van 2013). Thus, empirical data from ACVs is essential to iterate towards an applicable modelling framework. This is the basis for the current paper which is organised as follows: A state-of-the-art of ACVs is presented in Section 2 to show state-of-the-art design approaches. In Section 3, the structure of the modelling framework is illustrated and the concept elaborated. The modelling framework requires; computational fluid dynamics (CFD), contact mechanics including numerical methods suitable for design of ACVs; and modelling of fatigue and wear phenomena. These areas are reviewed through Sections 4–6 and the conclusions are given in Section 7.
Design and development of a digital stethoscope encapsulation for simultaneous acquisition of phonocardiography and electrocardiography signals: the SmartHeart case study
Published in Journal of Medical Engineering & Technology, 2020
Ricardo Baptista, Hugo Silva, Miguel Rocha
For easier concept development, functional decomposition is essential. In this process, product elemental functions are attributed to physical components. According to Hagedorn et al. [9], there is a close relationship between product function and clinical practice. Functional decomposition can therefore facilitate concept generation, based on practice specific underpinnings and clinical reasoning. Also, medical environments, medical regulations and diverse user base, requires simple function analysis to improve product development.