01- intro to syseng-lec1

7/31/2019 01- Intro to Syseng-Lec1

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Systems Engineering


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What is Systems Engineering?

Systems Engineering is an interdisciplinary

approach and means to enable the realization of

successful systems. It focuses on defining

customer needs and required functionality earlyin the development cycle, documenting

requirements, then proceeding with design

synthesis and system validation while

considering the complete problem.


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What is Systems Engineering?

Systems Engineering integrates all the disciplines

and specialty groups into a team effort forming a

structured development process that proceeds

from concept to production to operation. SystemsEngineering considers both the business and the

technical needs of all customers with the goal of

providing a quality product that meets the user

needs.

(Definition of the International Council on Systems

Engineering (INCOSE) )


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DEFINITION

A system is a regularly inter-acting

or interdependent group of elementsforming a unified whole.Thus,a system

is a collection of related parts treated as

a unit where its components interact.


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Websters Dictionary defines a

systemas an aggregation or

assemblage of objects untied by

some form of regular interaction or

independence.


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A group of diverse units combined bynature or art as to form an integral

whole, and to function, operate, or move

in obedience to some form of control.

In essence, a system constitutes a set of

interrelated components working toge-ther with common objective of fulfilling

some designated need.


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Asystem constitutes a complexcombination of resources in the

form of human beings, materials

equipment,software,facilities,data, money , and so on.


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Examples of a system

a. Transportationb.Communicationsc.Manufacturing Plantd.Power distributione.Information processingf. Waste disposalg.University/collegeh.Chemical processing plant officecomplexi. Electrical, electronic, mechanicalj. Office complexk.Other functional entities


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A system is contained within some

form of hierarchy. This reflects that

all systems are actually subsystems,since all are contained within some

larger system.

.


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Example:A bank includes such subsystems as:

a. The operations department

b. The commercial loan department

c. The consumer loan department

d. The savings department

The interconnections and interactions

among the subsystems are termedinterfaces


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THE STRUCTURE OF A SYSTEM

Systems are divided into threedistinct parts: inputs, processes

and outputs.They are surrounded by an

environment and frequently

include a feed back mechanismIn addition, a human, the decision

maker, is considered a part of the

system


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Inputs include those elements that enter

the system.

Examples:raw materials entering a chemical plant

patients admitted to a hospital

data input into a computer


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Processes are all the elements necessary toconvert or transform the inputs into

outputs.Examples:

In a chemical plant a process may include heating the

materials, using operating procedures, employing thematerials handling system, and using employees and

machines

In a hospital, process may include conducting tests

and performing a surgery.

In a computer, a process may include activating

commands, executing computations, and storing

information


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Outputs-describe the finished

products or theconsequences of being inthe system

Examples:Fertilizers are one output of a

chemical plant

Cured people are an output of ahospital

Reports may be the output of a

computerized system.


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System is separated from itsenvironment by a boundary.

The system is inside the boundary,whereas the environment liesoutside.

Boundaries may be physical (e.g., the systemis a department in Building C), or theboundary may be some non-physical factor.

For example, a system can be bounded bytime. In such a case we may analyze, anorganization for a period of only one year.


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Feedback, which appears as aclosed loop, is a flow ofinformation from outputcomponent to the decisionmaker concerning the

systems outputperformance.

Based on this information thedecision maker, who acts asa control may decide to

modify the inputs or the


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Environmentof the system is composed of

several elements that lie outside it in the

sense that they are not inputs, outputs,or processes.


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However, they have an impact on the

systems performance and consequently

on the attainment of its goals.

Environmental elements can be social,

political, legal, physical, and economical.

Example:

In the case of a chemical plant, the

suppliers, competitors, and customers are ele-

ments of the environment.


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CLASSIFICATIONS OF SYSTEM

Natural and Human-Made Systems

Physical and Conceptual Systems

Static and Dynamic Systems

Closed and Open Systems


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Natural and Human-Made Systems

Natural systems are those cameinto being by natural processes.This exhibits a high degree oforder and equilibrium. ( Ex. food

chain, water cycle) Human - madesystems are those in whichhuman beings have intervened.A river system is a natural system and

construction of dam became ahuman made system


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Open System and Closed System

System connected to itsenvironment by means of resource

flow is called an opensystem by thesame logic; a system that is notconnected to its environment is aclosed system.


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An open system allows information,

energy, and matter to cross its

boundaries. Open systems are self-regulatory and often self-adaptive.

Ex. Plants, ecological systems, and businessorganizations.

NOTE: When determining the impact of decisions on anopen system, we must check the relationship with the

environment and with related systems. In a closed system,

however, it is not necessary to conduct such checks because it

is assumed that the system is isolated.

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