homework1-seismica

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Gheorge Asachi Technical Uniovarsity of Iasi

Faculty of Civil Engeneering and Building Service

Master:Strcutural Engineering in English

Home Work No. 1

Systems Theory

Master student: Moraru Gabriel

Iasi, June 2013


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Home work No.1Systems Theory

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1. Definition1.1 Systems theory or general systems theory or systemics is an

interdisciplinary field which studies systems as a whole. Systems theory was foundedby Ludwig von Bertalanffy, William Ross Ashby and others between the 1940s and

the 1970s on principles from physics, biology and engineering and later grew into

numerous fields including philosophy, sociology, organizational theory, management,

psychotherapy (within family systems therapy) and economics among others.

Cybernetics is a closely related field. In recent times complex systems hasincreasingly been used as a synonym.

1.2 Systems theory is the interdisciplinary study ofsystems in general, with

the goal of elucidating principles that can be applied to all types of systems at all

nesting levels in all fields of research. The term does not yet have a well-established,

precise meaning, but systems theory can reasonably be considered a specialization of

systems thinking, a generalization ofsystems science, a systems approach. The term

originates from Bertalanffy's general system theory (GST) and is used in later efforts

in other fields, such as the action theory ofTalcott Parsons and the social systems

theory ofNiklas Luhmann.

1.3 Systems theory is a science which has the comparative study of systems

as its object. There are different types of systems: organisms (animals, humans,

particularly cognitive mechanisms in organisms), machines (particularly computers),physicochemical systems, psychic systems and social systems. Such a comparative

research program for heterogeneous types of systems presupposes a highly generalconcept of systems, for which numerous features have been proposed: the

interdependency of the parts of a system; the reference of any structure and process in

a system to the environments of the system; equilibrium and adaptedness and

continuous re-adaptations to environmental demands as core elements of the

understanding of a system; self-organization of a system as the principal way it

responds to external intervention; complexity as trigger mechanism for system-

formation and as the form which describes the internal network structures ofconnectedness among system elements.

2. ClasificationIn the branch concerned with work in the systems sciences as such, we can

distinguish between the purely theoretical development of systems ideas and their

interrelationships, and work aiming to develop systems ideas useful to interpreting

and/or handling real-world situations.General evolution theory is an example of the former, while the development of

social systems design methodology is an example of the latter. There are others
http://en.wikipedia.org/wiki/Ludwig_von_Bertalanffyhttp://en.wikipedia.org/wiki/William_Ross_Ashbyhttp://en.wikipedia.org/wiki/Interdisciplinaryhttp://en.wikipedia.org/wiki/Systemhttp://en.wikipedia.org/wiki/Systems_thinkinghttp://en.wikipedia.org/wiki/Systems_sciencehttp://en.wikipedia.org/wiki/Ludwig_von_Bertalanffyhttp://en.wikipedia.org/wiki/Systems_theory#General_systems_research_and_systems_inquiryhttp://en.wikipedia.org/wiki/Action_theory_(sociology)http://en.wikipedia.org/wiki/Talcott_Parsonshttp://en.wikipedia.org/wiki/Niklas_Luhmannhttp://en.wikipedia.org/wiki/Niklas_Luhmannhttp://en.wikipedia.org/wiki/Talcott_Parsonshttp://en.wikipedia.org/wiki/Action_theory_(sociology)http://en.wikipedia.org/wiki/Systems_theory#General_systems_research_and_systems_inquiryhttp://en.wikipedia.org/wiki/Ludwig_von_Bertalanffyhttp://en.wikipedia.org/wiki/Systems_sciencehttp://en.wikipedia.org/wiki/Systems_thinkinghttp://en.wikipedia.org/wiki/Systemhttp://en.wikipedia.org/wiki/Interdisciplinaryhttp://en.wikipedia.org/wiki/William_Ross_Ashbyhttp://en.wikipedia.org/wiki/Ludwig_von_Bertalanffy


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Master student Moraru Gabriel

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examples as well, leading to a three-fold distinction:

2.1 hardsystems approaches (such as are employed in systems engineering),

2.2 softsystems approaches (such as are drawn upon in humanistic

psychology), and mixed systems approachessuch as those employed in operationsresearch used as an aid to decision-making.

The classification of systems into hardandsoftrepresents an effort to draw

attention both to the degree of knowledge about a system, and about the system's

aims or purposes. Checkland developed this classification to represent two ends of acontinuum.

Hard systems are more easy to define and have more clear-cut aims or

purposes. They are typically the subject matter of engineers concerned with real-

world problem-solving: mechanisms, machines, aircraft, and power plants are

examples. Simplicity of purpose and clarity of boundary, however, do not necessarily

mean ease of design, operation, or maintenance: hard systems, as we know, canindeed be highly complex. At the other extreme aresoftsystems, characterized by

human beings as their principal components.

Such systems are difficult to define; they do not have clear-cut and agreed aims

or purposes. At the level of the individual psyche there are multiple processes of

perception, interpretation, representation, explanation, and communication that push

and pull at our individual and collective cognitive maps as they shape our subjective

image of phenomena and events. At

the level of a multiperson organization there are frequently different and conflicting

aims operating simultaneously. In both cases, the images and the aims of the system,

even if agreed upon, may change over time.

2.1.1 Systems engineering

The term systems engineering can be traced back to Bell Telephone

Laboratories in the 1940s. The need to identify and manipulate the properties of a

system as a whole, which in complex engineering projects may greatly differ from

the sum of the parts' properties, motivated the Department of Defense,NASA, andother industries to apply the discipline.

Systems engineering is an interdisciplinary approach and means for enabling

the realization and deployment of successful systems. It can be viewed as the

application of engineering techniques to the engineering of systems, as well as the

application of a systems approach to engineering efforts. Systems engineering

integrates other disciplines and specialty groups into a team effort, forming a

structured development process that proceeds from concept to production to

operation and disposal. Systems engineering considers both the business and the
http://en.wikipedia.org/wiki/Bell_Labshttp://en.wikipedia.org/wiki/Bell_Labshttp://en.wikipedia.org/wiki/United_States_Department_of_Defensehttp://en.wikipedia.org/wiki/NASAhttp://en.wikipedia.org/wiki/NASAhttp://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/Interdisciplinaryhttp://en.wikipedia.org/wiki/Systemhttp://en.wikipedia.org/wiki/Systemhttp://en.wikipedia.org/wiki/Interdisciplinaryhttp://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/NASAhttp://en.wikipedia.org/wiki/United_States_Department_of_Defensehttp://en.wikipedia.org/wiki/Bell_Labshttp://en.wikipedia.org/wiki/Bell_Labs


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technical needs of all customers, with the goal of providing a quality product that

meets the user needs.

Systems engineering is an interdisciplinary field ofengineering that focuses on

how to design and manage complex engineering projects over theirlife cycles. Issues

such as reliability, logistics, coordination of different teams (requirementmanagement), evaluation measurements, and other disciplines become more difficult

when dealing with large, complex projects.

Systems engineering deals with work-processes, optimization methods,

and risk management tools in such projects. It overlaps technical and human-centered

disciplines such as control engineering, industrial engineering,organizational studies,

and project management. Systems Engineering ensures that all likely aspects of a

project or system are considered, and integrated into a whole.

3. Modeling3.1 Origins and traditional scope

When it was no longer possible to rely on design evolution to improve upon a

system and the existing tools were not sufficient to meet growing demands, new

methods began to be developed that addressed the complexity directly. The

continuing evolution of systems engineering comprises the development and

identification of new methods and modeling techniques. These methods aid in bettercomprehension of engineering systems as they grow more complex. Popular tools

that are often used in the systems engineering context were developed during these

times, including USL, UML, QFD, and IDEF0.

In 1990, a professional society for systems engineering, the National Council

on Systems Engineering (NCOSE), was founded by representatives from a number of

U.S. corporations and organizations. NCOSE was created to address the need for

improvements in systems engineering practices and education. As a result of growing

involvement from systems engineers outside of the U.S., the name of the organizationwas changed to the International Council on Systems Engineering (INCOSE) in

1995. Schools in several countries offer graduate programs in systems engineering,

and continuing education options are also available for practicing engineers.

A system model is the conceptual model that describes and represents

a system. A system comprises multiple views such as planning, requirement

(analysis), design,implementation, deployment, structure, behavior, input data, and

output data views. A system model is required to describe and represent all these

multiple views.
http://en.wikipedia.org/wiki/Interdisciplinaryhttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Enterprise_life_cyclehttp://en.wikipedia.org/wiki/Reliabilityhttp://en.wikipedia.org/wiki/Logisticshttp://en.wikipedia.org/wiki/Risk_managementhttp://en.wikipedia.org/wiki/Control_engineeringhttp://en.wikipedia.org/wiki/Industrial_engineeringhttp://en.wikipedia.org/wiki/Organizational_studieshttp://en.wikipedia.org/wiki/Project_managementhttp://en.wikipedia.org/wiki/Universal_Systems_Languagehttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Quality_function_deploymenthttp://en.wikipedia.org/wiki/IDEFhttp://en.wikipedia.org/wiki/International_Council_on_Systems_Engineeringhttp://en.wikipedia.org/wiki/Continuing_educationhttp://en.wikipedia.org/wiki/Conceptual_modelhttp://en.wikipedia.org/wiki/Systemhttp://en.wikipedia.org/wiki/View_modelhttp://en.wikipedia.org/wiki/Planninghttp://en.wikipedia.org/wiki/Requirement_analysishttp://en.wikipedia.org/wiki/Requirement_analysishttp://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/Implementationhttp://en.wikipedia.org/wiki/System_deploymenthttp://en.wikipedia.org/wiki/Structurehttp://en.wikipedia.org/wiki/Behaviorhttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Input/outputhttp://en.wikipedia.org/wiki/Behaviorhttp://en.wikipedia.org/wiki/Structurehttp://en.wikipedia.org/wiki/System_deploymenthttp://en.wikipedia.org/wiki/Implementationhttp://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/Requirement_analysishttp://en.wikipedia.org/wiki/Requirement_analysishttp://en.wikipedia.org/wiki/Planninghttp://en.wikipedia.org/wiki/View_modelhttp://en.wikipedia.org/wiki/Systemhttp://en.wikipedia.org/wiki/Conceptual_modelhttp://en.wikipedia.org/wiki/Continuing_educationhttp://en.wikipedia.org/wiki/International_Council_on_Systems_Engineeringhttp://en.wikipedia.org/wiki/IDEFhttp://en.wikipedia.org/wiki/Quality_function_deploymenthttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Universal_Systems_Languagehttp://en.wikipedia.org/wiki/Project_managementhttp://en.wikipedia.org/wiki/Organizational_studieshttp://en.wikipedia.org/wiki/Industrial_engineeringhttp://en.wikipedia.org/wiki/Control_engineeringhttp://en.wikipedia.org/wiki/Risk_managementhttp://en.wikipedia.org/wiki/Logisticshttp://en.wikipedia.org/wiki/Reliabilityhttp://en.wikipedia.org/wiki/Enterprise_life_cyclehttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Interdisciplinary


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Master student Moraru Gabriel

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The system model describes and represents the multiple views possibly using

two different approaches. The first one is the non-architectural approach and the

second one is the architectural approach.

The non-architectural approach respectively picks a model for each view. For

example, Structured Systems Analysis and Design Method (SSADM), picking

the Structure Chart(SC) for structure description and the Data Flow Diagram (DFD)for behavior description, is categorized into the non-architectural approach.

The architectural approach, instead of picking many heterogeneous andunrelated models, will use only one single coalescence model. For example, System

architecture, using the Architecture Description Language (ADL) for both structure

and behavior descriptions, is categorized into the architectural approach.

3.2 Scope

One way to understand the motivation behind systems engineering is to see it

as a method, or practice, to identify and improve common rules that exist within a

wide variety of systems. Keeping this in mind, the principles of systems engineering

holism, emergent behavior, boundary, et al. can be applied to any system,

complex or otherwise, provided systems thinking is employed at all levels. Besides

defense and aerospace, many information and technology based companies, softwaredevelopment firms, and industries in the field of electronics & communications

require systems engineers as part of their team.

An analysis by the INCOSE Systems Engineering center of excellence(SECOE) indicates that optimal effort spent on systems engineering is about 15-20%

of the total project effort. At the same time, studies have shown that systems

engineering essentially leads to reduction in costs among other benefits. However, no

quantitative survey at a larger scale encompassing a wide variety of industries has

been conducted until recently. Such studies are underway to determine the

effectiveness and quantify the benefits of systems engineering. Systems engineering

encourages the use ofmodeling and simulation to validate assumptions or theories on

systems and the interactions within them.

Use of methods that allow early detection of possible failures, in safetyengineering, are integrated into the design process. At the same time, decisions made

at the beginning of a project whose consequences are not clearly understood can have

enormous implications later in the life of a system, and it is the task of the modern

systems engineer to explore these issues and make critical decisions. No method

guarantees today's decisions will still be valid when a system goes into service yearsor decades after first conceived. However, there are techniques that support the

process of systems engineering. Examples include soft systems methodology, Jay

Wright Forrester's System dynamics method, and theUnified Modeling

Language (UML)all currently being explored, evaluated, and developed to support

the engineering decision process.
http://en.wikipedia.org/wiki/Structured_Systems_Analysis_and_Design_Methodhttp://en.wikipedia.org/wiki/Structure_Charthttp://en.wikipedia.org/wiki/Data_Flow_Diagramhttp://en.wikipedia.org/wiki/System_architecturehttp://en.wikipedia.org/wiki/System_architecturehttp://en.wikipedia.org/wiki/Architecture_Description_Languagehttp://en.wikipedia.org/wiki/Systems_thinkinghttp://en.wikipedia.org/wiki/Modeling_and_simulationhttp://en.wikipedia.org/wiki/Safety_engineeringhttp://en.wikipedia.org/wiki/Safety_engineeringhttp://en.wikipedia.org/wiki/Jay_Wright_Forresterhttp://en.wikipedia.org/wiki/Jay_Wright_Forresterhttp://en.wikipedia.org/wiki/System_dynamicshttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/Unified_Modeling_Languagehttp://en.wikipedia.org/wiki/System_dynamicshttp://en.wikipedia.org/wiki/Jay_Wright_Forresterhttp://en.wikipedia.org/wiki/Jay_Wright_Forresterhttp://en.wikipedia.org/wiki/Safety_engineeringhttp://en.wikipedia.org/wiki/Safety_engineeringhttp://en.wikipedia.org/wiki/Modeling_and_simulationhttp://en.wikipedia.org/wiki/Systems_thinkinghttp://en.wikipedia.org/wiki/Architecture_Description_Languagehttp://en.wikipedia.org/wiki/System_architecturehttp://en.wikipedia.org/wiki/System_architecturehttp://en.wikipedia.org/wiki/Data_Flow_Diagramhttp://en.wikipedia.org/wiki/Structure_Charthttp://en.wikipedia.org/wiki/Structured_Systems_Analysis_and_Design_Method


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Bibliography

1. http://en.wikipedia.org/wiki/Systems_engineering2. http://en.wikipedia.org/wiki/Systems_theory

3. http://www.statpac.org/walonick/systems-theory.htm

4. Systems Theories:Their Origins, Foundations, and Development-By Alexander

Laszlo and Stanley Krippner
http://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/Systems_theoryhttp://www.statpac.org/walonick/systems-theory.htmhttp://www.statpac.org/walonick/systems-theory.htmhttp://en.wikipedia.org/wiki/Systems_theoryhttp://en.wikipedia.org/wiki/Systems_engineering

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