THE COST ON SYSTEM PERFORMANCE OF REQUIREMENTS ON DIFFERENTIABLE VARIABLES

2020 ◽  
pp. 1-8
Author(s):  
George A. Hazelrigg ◽  
Philip Stolfi
Keyword(s):  
System Design ◽  
System Performance ◽  
System Level ◽  
Management Approach ◽  
Design Management ◽  
Management Process ◽  
Undesirable Effect ◽  
Design Objective ◽  
System Requirements ◽  
The Cost

Abstract System design is commonly thought of as a process of maximizing a design objective subject to constraints, among which are the system requirements. Given system-level requirements, a convenient management approach is to disaggregate the system into subsystems, and to “flowdown” the system-level requirements to the subsystem or lower levels. We note, however, that requirements truly are constraints, and they impose a penalty on system performance. Furthermore, disaggregation of the system-level requirements into the flowdown requirements creates added sets of constraints, all of which have the potential to impose further penalties on overall system performance. This is a highly undesirable effect of an otherwise beneficial system design management process. This paper derives conditions that may be imposed on the flowdown requirements to assure that they do not penalize overall system performance beyond the system-level requirement.

Understanding the Impact of Decision Making on Robustness During Complex System Design: More Resilient Power Systems

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Joseph R. Piacenza ◽  
Kenneth John Faller ◽  
Mir Abbas Bozorgirad ◽  
Eduardo Cotilla-Sanchez ◽  
Christopher Hoyle ◽  
...  
Keyword(s):  
Complex System ◽  
Decision Making ◽  
System Design ◽  
Robust Design ◽  
System Performance ◽  
System Level ◽  
Individual Risk ◽  
Cascading Failure ◽  
The Impact ◽  
Complex System Design

Abstract Robust design strategies continue to be relevant during concept-stage complex system design to minimize the impact of uncertainty in system performance due to uncontrollable external failure events. Historical system failures such as the 2003 North American blackout and the 2011 Arizona-Southern California Outages show that decision making, during a cascading failure, can significantly contribute to a failure's magnitude. In this paper, a scalable, model-based design approach is presented to optimize the quantity and location of decision-making agents in a complex system, to minimize performance loss variability after a cascading failure, regardless of where the fault originated in the system. The result is a computational model that enables designers to explore concept-stage design tradeoffs based on individual risk attitudes (RA) for system performance and performance variability, after a failure. The IEEE RTS-96 power system test case is used to evaluate this method, and the results reveal key topological locations vulnerable to cascading failures, that should not be associated with critical operations. This work illustrates the importance of considering decision making when evaluating system level tradeoffs, supporting robust design.

Target Management in Complex System Design Using System Norms

2004 ◽  
Vol 127 (4) ◽  
pp. 536-544 ◽  
Author(s):  
H. Mahmoud ◽  
P. Kabamba ◽  
A. G. Ulsoy ◽  
G. Brusher
Keyword(s):  
Complex System ◽  
System Design ◽  
Output Signal ◽  
System Performance ◽  
Mimo Systems ◽  
System Level ◽  
Engineering System ◽  
Subsystem Design ◽  
Target Management ◽  
Complex System Design

The problem of setting, balancing, and determining priorities of design targets among the subsystems constituting an engineering system, i.e., managing the targets, is addressed. A new norm-based benchmarking approach is proposed to relate the system-level design objectives to subsystem design targets. The proposed approach provides a systematic means of setting and balancing subsystem design targets to deliver the desired system performance and ranks the priorities of the subsystem targets. Furthermore, the use of system norms, rather than output signal norms, to quantify system and subsystem performance reduces the number of design targets in multi-input multi-output (MIMO) systems. The approach is illustrated on a vehicle example, consisting of a frame, body, and body mounts as the subsystems.

Is Verifying Frequently an Optimal Strategy? A Belief-Based Model of Verification

2020 ◽  
Author(s):  
Aditya U. Kulkarni ◽  
Alejandro Salado ◽  
Christian Wernz ◽  
Peng Xu
Keyword(s):  
System Design ◽  
Optimal Strategy ◽  
Theoretical Foundation ◽  
Cost Effective ◽  
Single System ◽  
System Requirement ◽  
System Requirements ◽  
The Cost ◽  
Verification Strategy ◽  
Stakeholder Needs

Abstract Verification activities increase an engineering team’s confidence in its system design meeting system requirements, which in turn are derived from stakeholder needs. Conventional wisdom suggests that the system design should be verified frequently to minimize the cost of rework as the system design matures. However, this strategy is based more on experience of engineers than on a theoretical foundation. In this paper, we develop a belief-based model of verification of system design, using a single system requirement as an abstraction, to determine the conditions under which it is cost effective for an organization to verify frequently. We study the model for a broad set of growth rates in verification setup and rework costs. Our results show that verifying a system design frequently is not always an optimal verification strategy. Instead, it is only an optimal strategy when the costs of reworking a faulty design increase at a certain rate as the design matures.

scholarly journals Review on Building-Integrated Photovoltaics Electrical System Requirements and Module-Integrated Converter Recommendations

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1532 ◽  
Author(s):  
Simon Ravyts ◽  
Mauricio Dalla Vecchia ◽  
Giel Van den Broeck ◽  
Johan Driesen
Keyword(s):  
System Level ◽  
Electrical System ◽  
Building Integrated Photovoltaics ◽  
Building Integrated Photovoltaic ◽  
Engineering Costs ◽  
System Requirements ◽  
Safety Features ◽  
The Cost ◽  
The Impact ◽  
Electrical Installation

Since building-integrated photovoltaic (BIPV) modules are typically installed during, not after, the construction phase, BIPVs have a profound impact compared to conventional building-applied photovoltaics on the electrical installation and construction planning of a building. As the cost of BIPV modules decreases over time, the impact of electrical system architecture and converters will become more prevalent in the overall cost of the system. This manuscript provides an overview of potential BIPV electrical architectures. System-level criteria for BIPV installations are established, thus providing a reference framework to compare electrical architectures. To achieve modularity and to minimize engineering costs, module-level DC/DC converters preinstalled in the BIPV module turned out to be the best solution. The second part of this paper establishes converter-level requirements, derived and related to the BIPV system. These include measures to increase the converter fault tolerance for extended availability and to ensure essential safety features.

KINERJA iLEARNING RAHARJA ASK AND NEWS (IRAN) DALAM MENDUKUNG KEGIATAN TRIDHARMA IDUHELP!

CCIT Journal ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 18-33
Author(s):  
Untung Rahardja ◽  
Meta Amalya Dewi ◽  
Fitri Lisnawati
Keyword(s):  
Information Technology ◽  
System Performance ◽  
Communication Media ◽  
Related Method ◽  
Literature Reviews ◽  
The World ◽  
Information And Communication ◽  
System Requirements ◽  
Three Stages ◽  
Care System

Advances in information technology and communications which we achieve now actually been recognized and felt in the world of education in general. Currently College Prog implement a Tridharma terms Tridharma iDuHelp!. Tridharma is one of the basic responsibilities that students must be developed simultaneously and together. In this Tridharma still there are problems in the system iDuHelp! service. So IRAN (iLearning Prog Ask and News) in collaboration with iDuHelp! in providing answers and information needed by the student. In its application in Tridharma iDuHelp! IRAN There is a related method in it, such as iLearning methods that are currently being developed. With iLearning method can facilitate conduct research in detail, accurately, and clearly by using mindmapping. Besides the method of analysis is also done with three stages  namely the identification of the problem, identifying needs, and identifying system requirements. In this study using 4 literature reviews that can be used as references in preparing this paper. In this article explained about the problems that arise and solving problems in accurately using the flow Flowchart. In the implementation of the prototype shown iDuHelp! As well as the performance of Iran. So the end result of the study is a system performance to information and communication media of Iran can maximize iDuHelp! care system  It is widely integrated in a university.

Budgetary Authority and Coalition Management

2018 ◽  
Author(s):  
Paul Chaisty ◽  
Nic Cheeseman ◽  
Timothy J. Power
Keyword(s):  
Resource Dependence ◽  
Economic Resources ◽  
System Level ◽  
Energy Prices ◽  
Economic Crises ◽  
Government Transparency ◽  
Discretionary Spending ◽  
The Cost ◽  
Coalition Size

This chapter considers how presidents use their budget powers and the allocation of targeted discretionary spending to manage their coalitions. It considers the costs of budget tool deployment (in terms of time, controversy, and economic resources), and the factors that affect these costs: system-level factors (government transparency, federalism, personal-vote elections), coalition-level factors (coalition size, fragmentation, and heterogeneity), and conjunctural factors (economic crises and energy prices). It explores these factors with cases of budget tool deployment in Ukraine, Ecuador, and Russia. The Ecuadorean and Russian cases illustrate the divergent effects of resource dependence on the cost of budget tool dependence. Finally, it uses data from MP surveys to show the high value that legislators attribute to budget tools, and to illustrate how the composition of coalitions affects the costs that presidents are likely to face.

Significance of Lower Body Postures in Chair Design

2021 ◽  
pp. 001872082110270
Author(s):  
Seulgi Kim ◽  
Ilseok Lee ◽  
Sang Hyeon Kang ◽  
Sangeun Jin
Keyword(s):  
Lower Extremity ◽  
Lumbar Lordosis ◽  
System Level ◽  
Lumbar Region ◽  
Muscle Recruitment ◽  
Knee Angle ◽  
Activity Measures ◽  
Head Flexion ◽  
Kinematic Measures ◽  
The Cost

Objective This study examined a system-level perspective to investigate the changes in the whole trunk and head postures while sitting with various lower extremity postures. Background Sitting biomechanics has focused mainly on the lumbar region only, whereas the anatomy literature has suggested various links from the head and lower extremity. Method Seventeen male participants were seated in six lower extremity postures, and the trunk kinematics and muscle activity measures were captured for 5 s. Results Changes in the trunk-thigh angle and the knee angle affected the trunk and head postures and muscle recruitment patterns significantly, indicating significant interactions between the lower extremity and trunk while sitting. Specifically, the larger trunk-thigh angle (T135°) showed more neutral lumbar lordosis (4.0° on average), smaller pelvic flexion (1.8°), smaller head flexion (3.3°), and a less rounded shoulder (1.7°) than the smaller one (T90°). The smaller knee angle (K45°) revealed a more neutral lumbar lordosis (6.9°), smaller pelvic flexion (9.2°), smaller head flexion (2.6°), and less rounded shoulder (2.4°) than the larger condition (K180°). The more neutral posture suggested by the kinematic measures confirmed significantly less muscular recruitment in the trunk extensors, except for a significant antagonistic co-contraction. Conclusion The lower and upper back postures were more neutral, and back muscle recruitment was lower with a larger trunk-thigh angle and a smaller knee angle, but at the cost of antagonistic co-contraction. Application The costs and benefits of each lower extremity posture can be used to design an ergonomic chair and develop an improved sitting strategy.

To err is system; a comparison of methodologies for the investigation of adverse outcomes in healthcare

2021 ◽  
pp. 251604352199026
Author(s):  
Peter Isherwood ◽  
Patrick Waterson
Keyword(s):  
Patient Safety ◽  
System Performance ◽  
Healthcare Delivery ◽  
Healthcare Providers ◽  
Real Life ◽  
Adverse Outcomes ◽  
System Level ◽  
Future Performance ◽  
System A ◽  
Regulatory Bodies

Patient safety, staff moral and system performance are at the heart of healthcare delivery. Investigation of adverse outcomes is one strategy that enables organisations to learn and improve. Healthcare is now understood as a complex, possibly the most complex, socio-technological system. Despite this the use of a 20th century linear investigation model is still recommended for the investigation of adverse outcomes. In this review the authors use data gathered from the investigation of a real life healthcare near incident and apply three different methodologies to the analysis of this data. They compare both the methodologies themselves and the outputs generated. This illustrates how different methodologies generate different system level recommendations. The authors conclude that system based models generate the strongest barriers to improve future performance. Healthcare providers and their regulatory bodies need to embrace system based methodologies if they are to effectively learn from, and reduce future, adverse outcomes.

scholarly journals An Optimized Mathematical Model for Items Supplies Planning of a Logistic System

2016 ◽  
Vol 10 (10) ◽  
pp. 133
Author(s):  
Mohammad Ali Nasiri Khalili ◽  
Mostafa Kafaei Razavi ◽  
Morteza Kafaee Razavi
Keyword(s):  
Mathematical Model ◽  
Mixed Integer ◽  
Logistics System ◽  
Proposed Model ◽  
Multiple Objective Decision Making ◽  
System Requirements ◽  
Purchasing Logistics ◽  
The Cost ◽  
The Mathematical Model ◽  
First Time

Items supplies planning of a logistic system is one of the major issue in operations research. In this article the aim is to determine how much of each item per month from each supplier logistics system requirements must be provided. To do this, a novel multi objective mixed integer programming mathematical model is offered for the first time. Since in logistics system, delivery on time is very important, the first objective is minimization of time in delivery on time costs (including lack and maintenance costs) and the cost of purchasing logistics system. The second objective function is minimization of the transportation supplier costs. Solving the mathematical model shows how to use the Multiple Objective Decision Making (MODM) can provide the ensuring policy and transportation logistics needed items. This model is solved with CPLEX and computational results show the effectiveness of the proposed model.

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