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functional-requirement
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Management of System Requirements in Systems Engineering Process with Axiomatic Design Principles
, M.Sc. Thesis Sharif University of Technology ; Malaek, Mohammad Bagher (Supervisor)
Abstract
Functional Requirements (FR) are traditionally known to be "input" as far as an engineering process is concerned. However, for a Systems Engineer (SE), this is not the case. A well-known task of a SE is, in fact, to develop FRs from what is considered as the customer needs. The traditional approach to develop suitable FRs involves an algorithmic procedure; which mostly relies on the skills, knowledge, attitude, and experiences of the SE or experts members of design team. It is therefore an ad-hoc method which results in quite a few numbers of trial-errors and its effectiveness only reveals itself as time goes on. The current work aims to address such a shortcoming in Systems Engineering...
Using axiomatic design theory for selection of the optimum design solution and manufacturing process plans of a limited angle torque motor
, Article Journal of Manufacturing Science and Engineering, Transactions of the ASME ; Vol. 136, Issue. 5 , 2014 ; ISSN:1096-6668 ; Houshmand, M ; Nasiri-Zarandi, R ; Mirsalim, M ; Sharif University of Technology
Abstract
The brushless dc limited angle torque motor (LATM) has been widely used in areas of aerospace equipments, robot drives, optical scanning systems and any drive systems that require limited motion, ranging from the simple ON-OFF servo valves to the accurate tracking of a reference signal. This paper presents the optimum design procedure of a brushless direct current LATM to satisfy the functional requirements (FRs) and constraints using Independence axiom in axiomatic design (AD) approach. Also, to select the best manufacturing process plan, we consider both cost and thermal performance as two effective criteria, and evaluate available alternatives by computing information content in...
Improve Product Development Cost Estimation Models Using Axiomatic Design
, M.Sc. Thesis Sharif University of Technology ; Hushmand, Mahmoud (Supervisor)
Abstract
Considering the competitive environment of businesses, organizations are forced to focus on reduction of product life cycle. Product development processes are usually start with the idea “customer’s needs” and its evaluation, and then implementation testing, marketing and etc. To maintain competiveness the process of product development should be considered continuously. Since the life cycle of products are reducing by introduction of new technologies, one may select the strategy of product development by changing the functions of the current product. Annual exhibitions that are involved in innovations, where technology-driven organizations participates to introduce their new products...
Functional process capability analysis in mechanical systems
, Article International Journal of Advanced Manufacturing Technology ; Vol. 73, issue. 5-8 , July , 2014 , p. 899-912 ; 02683768 ; Movahhedy, M. R ; Sharif University of Technology
Abstract
Functional quality in the mechanical products is governed mainly by the degree of satisfaction of the design requirements, which itself depends on the variations in the effective variables. The functional parameters cannot be easily measured in mass production, and thus, are not usually considered as a direct inspection objective. Process capability indices are useful tools for evaluating the ability of a process to produce the dependent variables of a product that meet certain specifications. In this paper, the conventional process capability concept is extended to develop a computational tool for analysis of the functional quality of a mechanical product. Through defining new proper...
A statistical solution to mitigate functional requirements coupling generated from process (manufacturing) variables integration-part I
, Article Procedia CIRP, 16 September 2015 through 18 September 2015 ; Volume 34 , 2015 , Pages 69-75 ; 22128271 (ISSN) ; Houshmand, M ; Sharif University of Technology
Abstract
Utilizing the Axiomatic Design (AD) principles to develop a perfect product, design of a manufacturing system with minimal complexity is required. For the purpose of reducing the manufacturing system complexity, theoretically, it is preferred to integrate multiple Process Variables (PVs) of the product into a single process unit. However, due to significant presence of some active noise factors, this integration practice may result in failing to maintain the independence among some of Functional Requirements (FRs) of the product. This event is the result of statistical causal relationships unintentionally developed among a subset of the integrated PVs. In such a condition, the AD's...
A statistical solution to mitigate functional requirements coupling generated from process (manufacturing) variables integration-part 2: a case study on clarifying the effect of process (manufacturing) variables integration on functional requirements independency
, Article Procedia CIRP, 16 September 2015 through 18 September 2015 ; Volume 34 , September , 2015 , Pages 76-80 ; 22128271 (ISSN) ; Houshmand, M ; Sharif University of Technology
Abstract
In this part of the work, to illustrate the strength of the "partial and semipartial correlation analysis, as the proposed solution described in detail in part 1, we consider design problem of the manufacturing system of a given product based on a set of hypothetical data and show how to explore the most appropriate integration choices in which the (causal) dependencies of the concerned PVs are minimal. Based on the results of this study, we emphasize that incorporating the identified sensitive PVs into the integration process will eventually lead to coupling among a subset of the product's FRs and isolation of these PVs is recommended as an ideal solution. However, sometimes, in the real...
A comprehensive fuzzy feature-based method for worst case and statistical tolerance analysis
, Article International Journal of Computer Integrated Manufacturing ; Volume 29, Issue 1 , 2016 , Pages 42-63 ; 0951192X (ISSN) ; Movahhedy, M. R ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
Tolerance analysis is an analytical tool for the estimation of accumulating effects of the individual part tolerances on the functional requirements of a mechanical assembly. This article presents a comprehensive feature-based method for tolerance analysis of mechanical assemblies with both dimensional and geometric tolerances. In this method, dimensional and geometric tolerance zones are described by the combination of fuzzy modelling and small degrees of freedom (SDOF) concept. In this model, the uncertainty in dimensions and geometric form of features is mathematically described using fuzzy modelling, and the kinematic effects of tolerances in assemblies are expressed by SDOF concept. In...
A road map for knowledge management systems design using axiomatic design approach
, Article MATEC Web of Conferences, 13 September 2017 through 15 September 2017 ; Volume 127 , 2017 ; 2261236X (ISSN) ; Amani, M ; Slatineanu, L ; Sharif University of Technology
Abstract
Successful design and implementation of knowledge management systems have been the main concern of many researchers. It has been reported that more than 50% of knowledge management systems have failed, therefore, it is required to seek for a new and comprehensive scientific approach to design and implement it. In the design and implementation of a knowledge management system, it is required to know 'what we want to achieve' and 'how and by what processes we will achieve it'. A literature review conducted and axiomatic design theory selected for this purpose. For the first time, this paper develops a conceptual design of knowledge management systems by means of a hierarchical structure,...
A protocol for constraint automata execution in a synchronous network of processors
, Article 12th International Conference on Verification and Evaluation of Computer and Communication Systems, VECoS 2018, 26 September 2018 through 28 September 2018 ; Volume 11181 LNCS , 2018 , Pages 80-94 ; 03029743 (ISSN); 9783030003586 (ISBN) ; Izadi, M ; Habibi, J ; Sharif University of Technology
Springer Verlag
2018
Abstract
In service oriented computing we encounter the problem of coordinating autonomous services (e.g., micro-services) communicate within the deployment environments (e.g., multi-cloud infrastructures) but participate for the functional requirements. While the environments have the deployment concerns like real-time, security, privacy or even energy consumption constraints, for the sake of brevity, the formal models of coordination in service oriented systems generally abstract away these concerns and focus on the functional ones such as synchronization, data and context dependency constraints. In this paper, we consider Constraint Automata (CA) as a formal model of the functional behaviours for...
High performance and predictable memory controller for multicore mixed-criticality real-time systems
, Article IET Computers and Digital Techniques ; Volume 13, Issue 5 , 2019 ; 17518601 (ISSN) ; Farbeh, H ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
Multicore processors are widely used in today's real-time embedded systems to satisfy the performance and predictability requirements as well as reduce cost. A vast majority of multicore embedded systems are running several tasks with mixed-criticality, in which the non-functional requirements of the tasks are different or even conflicting. A major challenge in mixed-criticality systems is to maximise the efficiency of shared resources while satisfying the criticality requirements. Shared memory is a key component that should be well managed and memory controller plays the main role in this case. Several memory controllers have been introduced in the literature for multicore processors. In...
An aspect enhanced method of NFR modeling in software architecture
, Article 10th International Conference on Information Technology, ICIT 2007, Rourkela, 17 December 2007 through 20 December 2007 ; 2007 , Pages 240-242 ; 0769530680 (ISBN); 9780769530680 (ISBN) ; Mirian Hosseinabadi, H ; Chiniforooshan Esfahani, H ; Sharif University of Technology
2007
Abstract
Existence of crosscutting concerns in software requirements often intensifies complexity of software development process. Modeling and analyzing of these concerns in the software architecture decrease possibility of finding tangled and complex components in the ultimate design. Aspect oriented ADLs have emerged to overcome this problem; however, imposing radical changes to existing architectural modeling methods is not easily acceptable by architects. In this paper, we present a method to enhance conventional software architecture description languages through utilization of aspect features with special focuses on non-functional requirements (NFRs). © 2007 IEEE
Mapping state diagram to petri net : An approach to use markov theory for analyzing non-functional parameters
, Article 2006 International Conference on Systems, Computing Sciences and Software Engineering, SCSS 2006, Part of the International Joint Conferences on Computer, Information, and Systems Sciences, and Engineering, CISSE 2006, 4 December 2006 through 14 December 2006 ; 2007 , Pages 185-190 ; 9781402062636 (ISBN) ; Siasifar, M ; Montazeri, H ; Movaghar, A ; Zandakbari, M ; Sharif University of Technology
2007
Abstract
The quality of an architectural design of a software system has a great influence on achieving nonfunctional requirements to the system. Unified Modeling Language (UML), which is the industry standard as a common object oriented modeling language needs a well-defined semantic base for its notation. Integrating formal methods Petri nets (PNs) with object oriented design concepts UML is useful to benefit from the strengths of both approaches. Formalization of the graphical notation enables automated processing and analysis tasks. In this paper we use a method to converting State Diagram to Generalized Stochastic Petri Net (GSPN) and then we derive the embedded Continues Time Markov Chain from...
Fuzzy-small degrees of freedom representation of linear and angular variations in mechanical assemblies for tolerance analysis and allocation
, Article Mechanism and Machine Theory ; Volume 46, Issue 4 , April , 2011 , Pages 558-573 ; 0094114X (ISSN) ; Movahhedy, M. R ; Foumani, M. S ; Sharif University of Technology
2011
Abstract
Tolerances naturally generate an uncertain environment for design and manufacturing. In this paper, a novel fuzzy based tolerance representation approach for modeling the variations of geometric features due to dimensional tolerances is presented. The two concepts of fuzzy theory and small degrees of freedom are combined to introduce the fuzzy-small degrees of freedom model (F-SDOF). This model is suitable for tolerance analysis of mechanical assemblies with linear and angular tolerances. Based on the fuzzy concept, a new index (called the assemblability index) is introduced which signifies the fitting quality of parts in the assembly. Graphical and numerical representations of tolerance...
A multiple objective framework for optimal asymmetric tolerance synthesis of mechanical assemblies with degrading components
, Article International Journal of Advanced Manufacturing Technology ; Volume 100, Issue 9-12 , 2019 , Pages 2177-2205 ; 02683768 (ISSN) ; Sharif University of Technology
Springer London
2019
Abstract
In order to produce the mechanical assemblies with the high quality, the finest functionality, and the low cost, the optimal tolerance synthesis can be a useful tool in the design stage. The degradation of components due to some operational or environmental factors (such as the thermal cycling, the mechanical deformation, and the wear) can lead to dimensional variations in components and fall-off of the functionality of the product. In addition, different manners of the degradation on the internal and external dimensions can cause asymmetric deviations in the dimensions. On the other hand, the effect of degradation on the product quality has not been considered in most researches. In this...
A new procedure to determine equivalent strut of infill walls with openings for engineering applications
, Article Proceedings of the Institution of Civil Engineers: Structures and Buildings ; Volume 173, Issue 8 , 2020 , Pages 585-601 ; Noorifard, A ; Sharif University of Technology
ICE Publishing
2020
Abstract
In architecture, design of doors and windows for functional requirements, circulation, natural light and ventilation, aesthetics and view is inevitable. Parameters such as size, location and aspect ratio of the openings change the seismic behaviour of infilled frames. Ignoring these parameters in structural analysis may lead to substantial inaccuracy in predicting the lateral stiffness, strength and ductility of the frame. Despite numerous experimental and numerical studies on perforated infill walls in recent decades, the related provisions are rare in seismic codes and engineers tend not to use their results in analysis and design due to their complexity. The main purpose of this work was...
An evaluation method for aspectual modeling of distributed software architectures
, Article 6th IEEE/ACS International Conference on Computer Systems and Applications, AICCSA 2008, Doha, 31 March 2008 through 4 April 2008 ; 2008 , Pages 903-908 ; 9781424419685 (ISBN) ; Montaghami, V ; Safi, G ; Mirian Hosseinabadi, S. H ; Sharif University of Technology
2008
Abstract
Dealing with crosscutting requirements in software development usually makes the process more complex. Modeling and analyzing of these requirements in the software architecture facilitate detecting architectural risks early. Distributed systems have more complexity and so these facilities are much useful in development of such systems. Aspect oriented Architectural Description Languages(ADL) have emerged to represent solutions for discussed problems; nevertheless, imposing radical changes to existing architectural modeling methods is not easily acceptable by architects. Software architecture analysis methods, furthermore, intend to verify that the quality requirements have been addressed...