Download - Lect1-System Analysis
-
8/7/2019 Lect1-System Analysis
1/57
LECTURE 1
SYSTEM ANALYSIS
Stock Exchange = Pasar Modal
-
8/7/2019 Lect1-System Analysis
2/57
IMPORTANT MESSAGES
1. QUESTIONS
Why Is your system running well?, why?
Your study You may not know, then check
What is your final academic performance?, IP
-
8/7/2019 Lect1-System Analysis
3/57
Message Sejarah Pertanian
Berburu :Hasil 50 x lebih rendah dari menanam
Menanam: Hasil 1/50 dari industri
Pekerja Industri: Hasil 1/50 dari SmartBusinessmen (Entrepreneurs)
-
8/7/2019 Lect1-System Analysis
4/57
IMPORTANT MESSAGES
Can your system be improved?, how?
1. Specify your system in term of input, output andprocess
2. Determine the main product of your system
3. Set the target to be achieved
4. Check the process of input to produce the mainproduct
5. Check the main input limiting the main product
6. Check other factors influencing the conversion ofinput to the main product
7. Draw a diagram connecting input, output and other
factors
-
8/7/2019 Lect1-System Analysis
5/57
2. SYSTEM IMPROVEMENT
Planning Why build the system? How should you (the team) go about building it?
Analysis Who uses system,
what will it do, where and when will the system be used?
Design How will the system work?
Implementation System delivery
-
8/7/2019 Lect1-System Analysis
6/57
3. DATA FLOW DIAGRAMS (DFD)
-
8/7/2019 Lect1-System Analysis
7/57
-
8/7/2019 Lect1-System Analysis
8/57
LECTURE FLOW
INTRODUCTIONA. DEFINITION
B. OVERALL EMPHASIS
C. TYPES OF SYSTEMS ANALYSIS
D. WHY IS IT IMPORTANT?
E. SYSTEMS ANALYSIS USE
F. THE TERM OF SYSTEM ANALYSIS
BACKGROUND CONCEPT OF SYSTEMS
AN EXAMPLE OF SYSTEM ANALYSIS: SDLC
-
8/7/2019 Lect1-System Analysis
9/57
A. Background1. Many students failed to get the best academic
performance because they do not develop agood system of study
2. Many failed systems were abandoned becauseanalysts tried to build wonderful systemswithout understanding the organization.
3. The primarily goal is to create value for the
organization.
INTRODUCTION
-
8/7/2019 Lect1-System Analysis
10/57
3. Systems are becoming more complex, moresophisticated, and harder to understand
4. The characteristic attributes of a problem situationwhere systems analysis is called upon arecomplexity of the issue and uncertainty of theoutcome of any course of action that might
reasonably be taken5. The heavy reliance of most organisations on
information processing means that the analyst mustbe more accurate, and skilful, than ever before.
6. Systems analysis is an explicit formal inquiry carriedout to help someone (referred to as the decisionmaker) identify a better course of action and make abetter decision than he might otherwise have made
-
8/7/2019 Lect1-System Analysis
11/57
A. DEFINITION
What is Systems Analysis and Design (SAD)? Systems analysis means understanding the
existing system and defining the logicalrequirements for a new system prior to
designing the system System analysis is the analysis of the role of a
proposed system and the identification of therequirements that it should meet.
System analysis is the study of an activity orprocedure to determine the desired end and themost efficient method of obtaining this end
-
8/7/2019 Lect1-System Analysis
12/57
Systems analysis is the interdisci-
plinary part of science, dealing withanalysis of
sets of interacting entities, the systems,often prior to their automation as computersystems, and
the interactions within those systems.This field is closely related to operationsresearch.
Bagian saininterdisiplin yangberhubungandengananalisisserangkaian entitas yang berinteraksi (sistem), seringsebelum otomatisasi seperti sistem komputer,daninteraksidalam sistem
-
8/7/2019 Lect1-System Analysis
13/57
Systems Analysis: understanding and specifyingin detailwhat an information system should do
Attempts to understand how the existing
system helps solve the problem identified insystems investigation
System Design: specifying in detail howtheparts of an information system should be
implemented
-
8/7/2019 Lect1-System Analysis
14/57
Systems analysis is an explicit formal
inquiry carried out to help someone(referred to as the decision maker)identify a better course of action andmake a better decision than he might
otherwise have made Penyelidikan formaltegas untuk membantu
seseorang(pembuat keputusan)mengidentifikasisuaturangkaianaksi yanglebih baik dari yang
dapat sebaliknya buat
-
8/7/2019 Lect1-System Analysis
15/57
The systems analyst is a key person analyzing the business,
identifying opportunities for
improvement, and
designing information systems to
implement these ideas. It is important to understand and
develop through practice the skills
needed to successfully design andimplement new informationsystems.
-
8/7/2019 Lect1-System Analysis
16/57
B. OVERALL EMPHASIS
To gather data on the existing system
and the requirements for the new
system (mengumpulandatatentangsistem yg
adadan kebutuhanakan sistem yangbaru) To consider alternative solutions to the
problem and the feasibility of the
solutions (mempertimbangkan solusialternatifakanproblemdan kelayakan
solusi)
-
8/7/2019 Lect1-System Analysis
17/57
C. TYPES OF SYSTEMS ANALYSIS
Accident Analysis
Business analysis
Morphological analysis
Software prototyping
Spiral model
Waterfall model
-
8/7/2019 Lect1-System Analysis
18/57
INTRODUCTIONINTRODUCTION
D. WHY IS IT IMPORTANT?
Success of information systems depends on goodSAD
Widely used in industry - proven techniques
Part of career growth in IT - lots of interesting andwell-paying jobs!
Increasing demand for systems analysis skills
-
8/7/2019 Lect1-System Analysis
19/57
E. SYSTEMS ANALYSIS USE
1. The characteristic attributes of a problem situation wheresystems analysis is called upon are complexity of theissue and uncertainty of the outcome of any course ofaction that might reasonably be taken.
2. Systems analysis usually has some combination of the
following: identification and re-identification) ofobjectives, constraintS, and
alternative courses of action;
examination of the probable consequences of the alternatives interms of costs, benefits, and risks;
presentation of the results in a comparative framework so thatthe decision maker can make an informed choice from among thealternatives.
-
8/7/2019 Lect1-System Analysis
20/57
3. The typical use of systems analysis is to guide decisions
on issues such as national or corporate plans andprograms, resource use and protection policies,research and development in technology, regional andurban development, educational systems, and othersocial services.
4. Clearly, the nature of these problems requires aninterdisciplinary approach. There are several specifickinds or focuses of systems analysis for whichdifferent terms are used:
A systems analysis related to public decisions is often referredto as a POLICY ANALYSIS.
A systems analysis that concentrates on comparison andranking of alternatives on basis of their known characteristics is
referred to as DECISION ANALYSIS.
-
8/7/2019 Lect1-System Analysis
21/57
CONCEPT OF SYSTEMS
Basic TermsSystem: An organized relationship among the
functioning units or components, which work in syncto achieve a common goal.
System Study: A study of operations of a set ofconnected elements and the inter connectionsbetween these elements. It clearly shows that no onecan ignore an element while doing a system study.
System Approach: Shows a set of procedure tosolve a particular problem, It applies scientific methods
to understand the inter relationship between theelements to solve the problem.System analysis: It is a management exercise, which
helps us in designing a new system or improving theexisting system.
-
8/7/2019 Lect1-System Analysis
22/57
Concept of Systems
Characteristics of a system. A system can bedescribed as having nine characteristics
1. Components
2. Interrelations (of Components)
3. Boundary
4. Purpose5. Environment
6. Interfaces
7. Constraints
8. Input9. Output
-
8/7/2019 Lect1-System Analysis
23/57
Characteristics of a System
1. Components
Irreducible part
Or
Aggregation of parts that make a single object (e.g., a modemis a single object that is actually made of lots of circuits andswitches, etc.)
Aggregations are called subsystems
-
8/7/2019 Lect1-System Analysis
24/57
Characteristics of a System
2. Interrelations (of Components) Function of one component ties it to the function of others
within the system
Systemis workingtowardsomepurpose
-
8/7/2019 Lect1-System Analysis
25/57
Characteristics of a System
3) Boundary what separates the system from its environment
the system lies within the boundary
-
8/7/2019 Lect1-System Analysis
26/57
Characteristics of a System
4) Purpose Overall goal or function ofthe system
In structured systemsdesign, one rule is anysystem you cannot
describe in a single phraseis actually more than onefunction
But complex system has lots of subsystems with their own functions
e.g. human system is to live but w/ sub systems to breed(reproductive system), eat (digestive system), etc.
-
8/7/2019 Lect1-System Analysis
27/57
Characteristics of a System
5) Environment Made up of
components as well
Are components
important? Yes
Are componentsunder our control?No
Note that we do influence environment with outputs. But do notcontrol
Examples: political, social, economical, ecological
-
8/7/2019 Lect1-System Analysis
28/57
Characteristics of a System
6)Interfaces Points at which thesystem meets itsenvironment
Also exist betweensubsystems
In computer systems external interfaces are Public and internal
are Private Private interfaces can either be for privacy or to eliminate
extraneous information (and reduce potential mistakes or infooverload.
-
8/7/2019 Lect1-System Analysis
29/57
Characteristics of a System
7) ConstraintsLimitations
Can be internal (e.g.,resources)
Can be external (e.g.,
rules and realities)
Constraints are limits to what a system can do as a result ofexternal rules and realities or internal decisions
-
8/7/2019 Lect1-System Analysis
30/57
Characteristics of a System
8) Input A system takes input from its environment in order to function
Starts the cascade of the system
-
8/7/2019 Lect1-System Analysis
31/57
Characteristics of a System
9) Output Output is what a systemreturns to itsenvironment as a result ofachieving its purpose
In information systems,you have inputs,processing, and outputs ofdata
Process is the function of the (sub)systemInputs are what data it takes in
Outputs are the data or information result of the processing Example, fdouble(x) = x*2 is function.
If input is 5, output is 10.
-
8/7/2019 Lect1-System Analysis
32/57
Modeling- Whatis modeling?
Data reduction of key points
Omits extraneous points
What makes detail extraneous?
Many levels of abstraction Why multiple levels?
What items go on a given model level (does thegalaxy belong on the same level of abstraction as a
skin cell when describing the universe?)
Concept of Systems
-
8/7/2019 Lect1-System Analysis
33/57
THANK YOU
MATURNUWN
-
8/7/2019 Lect1-System Analysis
34/57
AN EXAMPLE OF SYSTEMANALYSIS:
SYSTEMS DEVELOPMENT LIFE
CYCLE (SDLC)
-
8/7/2019 Lect1-System Analysis
35/57
Systems Development Life Cycle
With the concept of systems in mind, lets talk about how
we build information systems We design/build/integrate information systems with what is
called the Software Development Lifecycle (SDLC)
SDLC is a description of any of the methods used bycompanies to create and maintain systems that perform basic
business functions Main goal is to improve employee efficiency by applying
software solutions to key business tasks A validated methodology should be used in order to improve odds of
success. Methodologies are used to manage the SDLC. We talk about
methodologies later. Note: the book calls SDLC itself a methodology, but I disagree with use
of term in that way. Generally speaking, methodologies are used tocomplete the SDLC, in whatever form it takes
-
8/7/2019 Lect1-System Analysis
36/57
So whatexactlyis the SDLC?
The systems developmentlifecycle(SDLC) is the process of understanding how an information
system (IS) can support business needs, designing the
system, building it, and delivering it to users
a series of steps used to manage the phases ofdevelopment for an information system
Phases are not necessarily sequential
Each phase has a specific outcome and deliverable
Individual companies use customized life cycle (different
phases, sub-phases, sequence) An alternative view from the books (the Spiral model) is shown
in the final slide FYI
-
8/7/2019 Lect1-System Analysis
37/57
Major Attributes of the Life Cycle
The project -- Moves systematically through phases where
each phase has a standard set of outputs
Produces project deliverables
Uses deliverables in implementation
Results in actual information system
Uses gradualrefinement
-
8/7/2019 Lect1-System Analysis
38/57
Systems Development Life Cycle (SDLC)
Four phase SDLC in book is simply used as a example
and is useful for purpose of teaching about systemsanalysis and design (SA&D):
1. Planning and Selection2. Analysis
3. Design
4. Implementation and Operation
-
8/7/2019 Lect1-System Analysis
39/57
Project Phases
Planning Why build the system? How should the team go about building it?
Analysis
Who uses system, what will it do, where and when will the system be used?
Design How will the system work?
Implementation System delivery
-
8/7/2019 Lect1-System Analysis
40/57
A simple process for making lunch
-
8/7/2019 Lect1-System Analysis
41/57
Project initiation
1. Identifying business valueIdentifying needs
Selecting from alternatives
Rough out solution plan
2. Analyze feasibility
Project management
1. Develop work plan
2. Staff the project3. Control and direct project
Planning
-
8/7/2019 Lect1-System Analysis
42/57
The Planning phase is the fundamental
process of understanding why aninformation system should be built.
The Planning phase will also determine
how the project team will go about buildingthe information system.
The Planning phase is composed of two
planning steps.
-
8/7/2019 Lect1-System Analysis
43/57
1. During project initiation, the systems
business value to the organization is
identified (How will it lower costs or increase
revenues?)2. During project management, the project
manager creates a work plan, staffs the
project, and puts techniques in place to help
the project team control and direct theproject through the entire SDLC.
-
8/7/2019 Lect1-System Analysis
44/57
Analysis strategy
Gathering business requirements
Requirements definition use cases
Process modeling
Data modeling
Analysis
-
8/7/2019 Lect1-System Analysis
45/57
Analysis strategy
Gathering business requirements
Requirements definition use cases
Process modeling
Data modeling
Analysis
-
8/7/2019 Lect1-System Analysis
46/57
The analysis phase answers the questions of who will use the system,
what the system will do, and
where and when it will be used. During this phase the project team
investigates any current system(s),
identifies improvement opportunities, and
develops a concept for the new system. This phase has three analysis steps.
-
8/7/2019 Lect1-System Analysis
47/57
Three Analysis Steps
1. Analysis strategy: This is developed to guidethe projects teams efforts. This includes ananalysis of the current system.
2. Requirements gathering: The analysis of this
information leads to the development of aconcept for a new system. This concept is usedto build a set of analysis models.
3. System proposal: The proposal is presented
to the project sponsor and other key individualswho decide whether the project shouldcontinue to move forward.
-
8/7/2019 Lect1-System Analysis
48/57
The system proposal is the initial deliverable thatdescribes what business requirements the new
system should meet. The deliverable from this phase is both an analysis
and a high-level initial design for the new system.
-
8/7/2019 Lect1-System Analysis
49/57
Design selection
Architecture design
I
nterface design Data storage design
Program design
Design
-
8/7/2019 Lect1-System Analysis
50/57
In this phases it is decided how the system will operate, in terms of the
hardware, software, and networkinfrastructure;
the user interface, forms, and reports that willbe used; and
the specific programs, databases, and files that
will be needed.
-
8/7/2019 Lect1-System Analysis
51/57
Five Design Steps
1. Design Strategy:
This clarifies whether thesystem will be developed by the companyor outside the company.
2. Architecture Design:This describes thehardware, software, and network
infrastructure that will be used.3. Database and File Specifications:These
documents define what and where the datawill be stored.
4. Program Design:
Defines what programsneed to be written and what they will do.
-
8/7/2019 Lect1-System Analysis
52/57
Construction
Program building
Program and system testing
Installation Conversion strategy
Training plan
Support plan
Implementation
-
8/7/2019 Lect1-System Analysis
53/57
During this phase, the system is eitherdeveloped or purchased (in the case of
packaged software).
This phase is usually the longest and mostexpensive part of the process.
The phase has three steps.
Implementation
-
8/7/2019 Lect1-System Analysis
54/57
Three Implementation Steps
1.System Construction: The systemis built and tested to make sure it
performs as designed.2.Installation: Prepare to support the
installed system.
3.Support Plan: Includes a post-implementation review.
-
8/7/2019 Lect1-System Analysis
55/57
Summary1. The Systems Development Lifecycle consists of four stages:
Planning, Analysis, Design, andImplementation
2. There are six major development methodologies:
the waterfall method, the parallel development method, the phased development method, system prototyping, design prototyping, and agile development.
3. There are five major team roles: business analyst, systems analyst, infrastructure analyst, change management analyst and project manager.
-
8/7/2019 Lect1-System Analysis
56/57
SystemsAnalysisand DesignSystemsAnalysisand Design,, 22ndndEdition:Edition: Alan Dennisand Barbara Haley Wixom John Wiley & Sons, Inc.
Prepared by: RobertaM. Roth, University ofNorthern Iowa
PowerPointPresentation forDennis & Haley Wixom, Systems Analysis and Design, 2ndEdition Copyright 2003 John Wiley & Sons, Inc. Allrightsreserved.
AP/ITEC 3010.03 Systems Analysis and Design, IAP/ITEC 3010.03 Systems Analysis and Design, ICourseCourse
IntroductionIntroduction Prof. PeterKhaiter
Email [email protected], Class web sitehttp://www.atkinson.yorku.ca/~pkhaiter/ITECw103010N.htm
-
8/7/2019 Lect1-System Analysis
57/57
Copyright 2003
John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond
that permitted in Section 117 of the 1976 United States CopyrightAct without the express written permission of the copyright owner is
unlawful. Request for further information should be addressed to the
Permissions Department, John Wiley & Sons, Inc.
The purchaser may make back-up copies for his/her own use only andnot for redistribution or resale.
The Publisher assumes no responsibility for errors, omissions, ordamages, caused by the use of these programs or from the use of theinformation contained herein.