Systems analysis and design lecture 1

Course Overview
 I. Systems Planning
 II. Systems Analysis
 III. Systems Design
 IV. Systems Implementation
 V. Systems Support and Security
 VI. The Systems Analyst’s Toolkit
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Recommended Books:
Systems Analysis and Design, 11th Edition (2017) by Tilley and Rosenblatt, Cengage Learning

SYSTEMS PLANNING
 Systems planning is the first of five phases in the systems development life
cycle. This lecture provides an introduction to systems analysis and design
by describing the role of information technology in today’s dynamic
business environment
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Objectives
1. Describe the impact of information technology
2. Define systems analysis and design and the role of a systems analyst
3. Define an information system and describe its components
4. Explain how to use business profiles and models
5. Explain Internet business strategies and relationships, including B2C and B2B
6. Identify various types of information systems and explain who uses them
7. Distinguish among structured analysis, object- oriented analysis, and agile methods
8. Explain the waterfall model, and how it has evolved
9. Discuss the role of the information technology department and the systems analysts
who work there

Lecture 1: Introduction to Systems
Analysis and Design
1.1. Introduction.
 It is well known that information technology has a dramatic
impact on our civilization. Enterprises and individuals use
information as a way to increase productivity, deliver quality
products and services, maintain customer loyalty, and make
sound decisions. In a global economy with intense
competition, information technology can mean the
difference between success and failure.
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Figure1: The impact of IT on our
society
(Source:www.vector--‐eps.com)

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1.2 Information Technology (IT) defined:
 Information Technology is defined as the combination of hardware,
software and services that people use to manage, communicate and
share information.
• Business success depends on information technology.
• IT has a very significant impact on modern society.
• IT is the main driver of the “digital economy”. Advances in hardware,
software and connectivity can provide substantial benefits to enterprises and
individuals.
• While spending levels for IT can be affected by economic conditions, most
enterprises still give high priority to IT budgets. During good times, businesses
cannot afford to be left behind in IT deployment. And during economic
slowdowns, IT can be used to reduce operating costs and promote efficiency.

1.2.1 The shifting nature of Information Technology
 The history of IT is a fascinating study of human progress and
achievement. We are dazzled by the latest and greatest technology, just
as our parents and grandparents were astonished by the arrival of
television, space flight, and personal computing. It is important for IT
professionals, who live and work in this exciting world, to realize that each
technology advance is part of a long-term process that often brings
dramatic change, but never really ends.
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The story of IBM is a good example.
As its name suggests, International Business Machines was a
major supplier of office equipment and typewriters long before
the modern computer era. Herman Hollerith, who invented a
card that identified characters by the location of punched
holes, founded IBM’s predecessor company in 1896. A deck of
hundreds or even thousands of these cards could store data
that was easily sorted, queried, and printed by machines. This
system sounds archaic now, but punch card technology was a
huge advance that revolutionized the business world, and was
in use into the 1960s and beyond.
Figure 2: Clocking in using a Punch card
(Source: www.vectormarketing.com)

 Today, IBM is a globe-spanning company with several hundred thousand
employees. It has succeeded in part by constantly adapting to its changing
business environment. For example, while it was once known primarily as a
hardware company, today IBM makes a significant part of its revenue from
software and services. It also invests in its people and tries to hire the best
talent available. It has more patents and more Noble Prize winners than any
other IT company in history.
 Nowadays, most forward-thinking IT firms do not require their employees to
“punch in” at all. Working from home, “hoteling” using random offices as
needed, and global contracting has dramatically changed the definition of
“being at work.” No doubt future students will view our current technology
the same way we smile at punched cards.
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1.2.2 Systems Analysis and Design
 Systems analysis and design is a step-by- step process for developing
high-quality information systems. An information system combines
technology, people, and data to provide support for business functions
such as order processing, inventory control, human resources,
accounting, and many more. Some information systems handle routine
day-to-day tasks, while others can help managers make better decisions,
spot marketplace trends, and reveal patterns that might be hidden in
stored data.
 Talented people, including a mix of managers, users, network
administrators, web designers, programmers, and systems analysts,
typically develop information systems. Capable IT professionals like these
are always in demand, even in a slow economy.
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1.2.3 The Role of the Systems Analyst
 A systems analyst is a valued member of the IT department team who helps
plan, develop, and maintain information systems. Analysts must be excellent
communicators with strong analytical and critical thinking skills. Because
systems analysts transform business requirements into IT projects, they must be
business-savvy as well as technically competent, and be equally comfortable
with managers and programmers, who sometimes have different points of
view.
 Most companies assign systems analysts to the IT department, but analysts
also can report to a specific user area such as marketing, sales, or
accounting. As a member of a functional team, an analyst is better able to
understand the needs of that group and how IT supports the department’s
mission. Smaller companies often use consultants to perform systems analysis
work on an as- needed basis.
 On any given day, an analyst might be asked to document business
processes, test hardware and software packages, design input screens, train
users, and plan ecommerce websites. A systems analyst may occasionally
manage IT projects, including tasks, resources, schedules, and costs. To keep
managers and users informed, the analyst conducts meetings, delivers
presentations, and writes memos, reports, and documentation.
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1.3 Information system components
 A system is a set of related components that produces
specific results. For example, specialized systems route
Internet traffic, manufacture microchips, and control
complex entities like the Hubble Telescope. A mission-
critical system is one that is vital to a company’s
operations. An order processing system, for example, is
mission critical because the company cannot do business
without it.
 Every system requires input data. For example, a
computer receives data when a key is pressed or when a
menu command is selected. In an information system,
data consists of basic facts that are the system’s raw
material. Information is data that has been transformed
into output that is valuable to users.
 An information system has five key components, as shown
in Figure 3: hardware, software, data, processes, and
people.
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Figure 3: The components of an
information system

Hardware Software Data Processes People
1.3.1 Hardware
 Hardware consists of everything in the physical layer of the information system. For example, hardware
can include servers, workstations, networks, telecommunications equipment, fiber-optic cables, mobile
devices, scanners, digital capture devices, and other technology-based infrastructure. A large
concentration of servers working together is called a server farm. As new technologies emerge,
manufacturers race to market the innovations and reap the rewards.
 Hardware purchasers today face a wide array of technology choices and decisions. In 1965, Gordon
Moore, a cofounder of Intel, predicted that the number of transistors on an integrated circuit chip would
double about every 24 months. His concept, called Moore’s Law, has remained valid for 50 years.
Fortunately, as hardware became more powerful, it also became much less expensive. Large businesses
with thousands or millions of sales transactions require company-wide information systems and powerful
servers, which are often now in the cloud.
1.3.2 Software
 Software refers to the programs that control the hardware and produce the desired information or
results. Software consists of system software and application software. System software manages the
hardware components, which can include a single computer or a global network with many thousands
of clients. Either the hardware manufacturer supplies the system software or a company purchases it
from a vendor. Examples of system software include the operating system, security software that
protects the computer from intrusion, device drivers that communicate with hardware such as printers,
and utility programs that handle specific tasks such as data backup and disk management. System
software also controls the flow of data, provides data security, and manages network operations. In
today’s interconnected business world, network software is vitally important.
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 Application software consists of programs that support day-to-day business
functions and provide users with the information they need. Examples of
company-wide applications, called enterprise applications, include order
processing systems, payroll systems, and company communications networks.
On a smaller scale, individual users can boost productivity with tools such as
spreadsheets, presentation software, and database management systems.
 Application software includes horizontal and vertical systems. A horizontal
system is a system, such as an inventory or a payroll application, that can be
adapted for use in many different types of companies. A vertical system is
designed to meet the unique requirements of a specific business or industry,
such as an online retailer, a medical practice, or an auto dealership.
 Most companies use a mix of software that is acquired at various times. When
planning an information system, a company must consider how a new system
will interface with older systems, which are called legacy systems. For
example, a new human resources system might need to exchange data with
a legacy payroll application.
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1.3.3 Data
 Data is the raw material that an information system transforms into useful
information. An information system can store data in various locations, called
tables. By linking the tables, the system can display the specific information that
the user needs—no more, and no less.
 Figure 4 shows a payroll system that stores data in four separate tables. Notice
that the linked tables work together to supply 19 different data items to the
screen. A user can display any or all data items and filter the data to fit defined
limits. In this example, the user requested a list of employees who live in a certain
city and worked more than 40 hours in the last pay period. Jane Doe’s name was
the first to display.
1.3.4 Processes
 Processes describe the tasks and business functions that users, managers, and IT
staff members perform to achieve specific results. Processes are the building
blocks of an information system because they represent actual day-to-day
business operations. To build a successful information system, analysts must
understand business processes and document them carefully.
1.3.5 People
 People who have an interest in an information system are called stakeholders.
Stakeholders include the management group responsible for the system, the users
(sometimes called end users) inside and outside the company who will interact
with the system, and IT staff members, such as systems analysts, programmers,
and network administrators who develop and support the system.
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 Each stakeholder group has a vital interest in the information system, but
most experienced IT professionals agree that the success or failure of a
system usually depends on whether it meets the needs of its users. For that
reason, it is essential to understand user requirements and expectations
throughout the development process.
 Jane Doe’s Payroll Data
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Figure 4: An example of a payroll database. In a typical
payroll system, data is stored in separate tables that are
linked to form an overall database.

1.4 Business today
 To design successful systems, systems analysts must
understand a company’s business operations. Each situation
is different. For example, a retail store, a medical practice,
and a hotel chain all have unique information systems
requirements. As the business world changes, systems analysts
can expect to work in new kinds of companies that will
require innovative IT solutions.
 Business today is being shaped by three major trends: rapidly
increasing globalization, technology integration for seamless
information access across a wide variety of devices such as
laptops and smartphones, and the rapid growth of cloud-
based computing and software services. These trends are
being driven by the immense power of the Internet.
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1.4.1 The internet model
 Internet-based commerce is called ecommerce (electronic
commerce). Internet-based systems involve various hardware and
software designs, but a typical model is a series of webpages that
provides a user interface, which communicates with database
management software and a web-based data server. On mobile
devices, the user interacts with the system with an app, but the
same back-end services are accessed. As Internet- based
commerce continues to grow, career opportunities will expand
significantly for IT professionals such as web designers, database
developers, and systems analysts.
 Ecommerce includes two main sectors: B2C (business-to-consumer) and B2B
(business-to-business). Within these broad categories, competition is
dynamic, extreme, and global. Every day brings new ideas, new players,
and new ways to involve customers, suppliers, and hordes of social network
participants. The following sections discuss this rapidly changing
environment.
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1.4.2 B2C (Business-to-Consumer)
 Using the Internet, consumers can go online to purchase an enormous variety of
products and services. This new shopping environment allows customers to do
research, compare prices and features, check availability, arrange delivery, and
choose payment methods in a single convenient session. Many companies, such
as airlines, offer incentives for online transactions because web-based processing
costs are lower than traditional methods. By making flight information available
online to last-minute travelers, some airlines also offer special discounts on seats
that might otherwise go unfilled.
 B2C commerce is changing traditional business models and creating new ones.
For example, a common business model is a retail store that sells a product to a
customer. To carry out that same transaction on the Internet, the company must
develop an online store and deal with a totally different set of marketing,
advertising, and profit- ability issues. Some companies have found new ways to
use established business models. For example, eBay.com has transformed a
traditional auction concept into a popular and successful method of selling goods
and services. Other retailers seek to enhance the online shopping experience by
offering gift advisors, buying guides, how-to clinics, and similar features. In the
ecommerce battles, the real winners are online consumers, who have more
information, better choices, and the convenience of shopping at home.
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1.4.3 B2B (Business-to-Business)
 Although the business-to-consumer (B2C) sector is more familiar to retail
customers, the volume of business-to-business (B2B) transactions is many times
greater. Industry observers predict that B2B sales will increase sharply as more
firms seek to improve efficiency and reduce costs.
 Initially, electronic commerce between two companies used a data sharing
arrangement called electronic data interchange (EDI). EDI enabled
computer-to-computer data transfer, usually over private
telecommunications lines. Firms used EDI to plan production, adjust inventory
levels, or stock up on raw materials using data from another company’s
information system. As B2B volume soared, company-to-company
transactions migrated to the Internet, which offered standard protocols,
universal availability, and low communication costs. The main advantage of
the web is that it offers seamless communication between different hardware
and software environments, anywhere and anytime.
 Because it allows companies to reach the global marketplace, B2B is
especially important to smaller suppliers and customers who need instant
information about prices and availability. In an approach that resembles an
open marketplace, some B2B sites invite buyers, sellers, distributors, and
manufacturers to offer products, submit specifications, and transact business.
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 Most large firms and government agencies use supply chain management
(SCM) software. A supply chain refers to all the companies who provide
materials, services, and functions needed to provide a product to a customer.
For example, a Sherwin-Williams customer who buys a gallon of paint is at the
end of a chain that includes the raw material sources, packaging suppliers,
manufacturers, transporters, warehouses, and retail stores. Because SCM is
complex and dynamic, specialized software helps businesses manage
inventory levels, costs, alternate suppliers, and much more.
1.5 Modeling Business Operations
 Systems analysts use modeling to represent company operations and
information needs. Business process modeling involves a business profile and a
set of models that document business operations.
1.5.1 Business Profiles
 A business profile is an overview of a company’s mission, functions,
organization, products, services, customers, suppliers, competitors, constraints,
and future direction. Although much of this information is readily available, a
systems analyst usually needs to do additional research and factfinding. A
business profile is the starting point for the modeling process.
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1.5.2 Business Processes
 A business process is a specific set of transactions, events, and results that
can be described and documented. A business process model (BPM)
graphically displays one or more business processes, such as handling an
airline reservation, filling a product order, or updating a customer account.
The sales order example in Figure 1-8 shows a simple model that includes
an event, three processes, and a result.
 A rough sketch might be sufficient to document a simple business process.
For complex models, analysts can choose computer-based tools that use
business process modeling notation (BPMN).
 BPMN includes standard shapes and symbols to represent events,
processes, workflows, and more. Multipurpose application such as
Microsoft Visio, CASE tools such as Visible Analyst, or online diagramming
tools such as draw. io can be used to create BPMN models. Notice that the
draw.io model in Figure 6 uses BPMN symbols to represent the same sales
order process shown in Figure 5.
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1.6 Business Information systems
 In the past, IT managers identified an information system based on its
primary users. For example, administrative staff used office systems,
operational people used operational systems, middle managers used
decision support systems, and top managers used executive information
systems.
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Figure 5: A simple business model
might consist of an even, some
processes, and a result.
Today, those traditional labels no longer apply.
For example, all employees, including top
managers, use office productivity systems to do
their jobs.
Similarly, operational users often require decision
support systems to do their jobs. As business
changes, information use also changes, and now
it makes more sense to identify a system by its
functions and features, rather than by its users. A
new set of system definitions includes enterprise
computing systems, transaction processing
systems, business support systems, knowledge
management systems, and user productivity
systems
Figure 6. This sample uses BPMN to
represent the same events, processes
and workflow shown in Figure 5

1.6.1 Enterprise Computing
 Enterprise computing refers to information systems that support company-wide
operations and data management requirements. Wal-Mart’s inventory control system,
Boeing’s production control system, and Hilton Hotels’ reservation system are examples
of enterprise computing systems.
 The main objective of enterprise computing is to integrate a company’s primary
functions (such as production, sales, services, inventory control, and accounting) to
improve efficiency, reduce costs, and help managers make key decisions. Enterprise
computing also improves data security and reliability by imposing a company-wide
framework for data access and storage.
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In many large companies, applications called enterprise resource planning (ERP)
systems provide costeffective support for users and managers throughout the
company.
For example, a car rental company can use ERP to forecast customer demand for
rental cars at hundreds of locations. Because of its growth and potential, many
hardware and software vendors target the enterprise computing market and offer
a wide array of products and services. For example, Figure 7 highlights Microsoft
Dynamics as an ERP solution that can boost productivity.

 By providing a company-wide computing
environment, many firms have been able to
achieve dramatic cost reductions. Other
companies have been disappointed in the time,
money, and commitment necessary to
implement ERP successfully. A potential
disadvantage is that ERP systems generally
impose an overall structure that might or might
not match the way a company operates.
 By providing a company-wide computing
environment, many firms have been able to
achieve dramatic cost reductions. Other
companies have been disappointed in the time,
money, and commitment necessary to
implement ERP successfully. A potential
disadvantage is that ERP systems generally
impose an overall structure that might or might
not match the way a company operates.
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1.6.2 Transaction Processing
 Transaction processing (TP) systems process data generated by day-to-
day business operations. Examples of TP systems include customer order
processing, accounts receivable, and warranty claim processing.
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Figure 8. A single sales transaction consists of
six separate tasks, which the TP system
processes as a group
TP systems perform a series of tasks whenever a
specific transaction occurs. In the example
shown in Figure 8, a TP system
verifies the customer’s data, checks the
customer’s credit status, checks the stock
status, posts to accounts receivable, adjusts
the
inventory level, and updates the sales file. TP
systems typically involve large amounts of data
and are mission-critical systems because the
enterprise cannot function without them.
TP systems are efficient because they process a
set of transaction-related commands as a
group rather than individually. To protect data
integrity, however, TP systems ensure that if any
single element of a transaction fails, the system
does not process the rest of the transaction.

1.6.3 Business support
 Business support systems provide job-related information support to users at
all levels of a company. These systems can analyze transactional data,
generate information needed to manage and control business processes,
and provide information that leads to better decision making.
 The earliest business computer systems replaced manual tasks, such as
payroll processing. Companies soon realized that computers also could
produce valuable information. The new systems were called management
information systems (MIS) because managers were the primary users.
Today, employees at all levels need information to perform their jobs, and
they rely on information systems for that support.
 A business support system can work hand in hand with a TP system. For
example, when a company sells merchandise to a customer, a TP system
records the sale, updates the customer’s balance, and makes a
deduction from inventory. A related business support system highlights slow
or fast-moving items, customers with past- due balances, and inventory
levels that need adjustment.
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 To compete effectively, firms must collect production,
sales, and shipping data and update the company-wide
business support system immediately. The newest
development in data acquisition is called radio frequency
identification (RFID) technology, which uses high-
frequency radio waves to track physical objects, such as
the item shown in Figure 9. Major retailers such as Wal-
Mart, which requires its suppliers to add RFID tags to all
items, have fueled RFID’s dramatic growth.
 An important feature of a business support system is
decision support capability. Decision support helps users
make decisions by creating a computer model and
applying a set of variables.
 For example, a truck fleet dispatcher might run a series of
what-if scenarios to determine the impact of increased
shipments or bad weather. Alternatively, a retailer might
use what-if analysis to determine the price it must charge
to increase profits by a specific amount while volume and
costs remain unchanged.
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Figure 9 Items can be easily tracked an
monitored with RFID technology throughout the
shipping process (Source:
www.nullplus/photos.com

1.6.4 Knowledge management
 Knowledge management systems use a large
database called a knowledge base that allows users
to ind information by entering keywords or questions in
normal English phrases. A knowledge management
system uses inference rules, which are logical rules that
identify data patterns and relationships.
 The Wolfram Alpha website, shown in Figure 10,
describes itself as a “computational knowledge
engine.” It has a sophisticated natural language front
end that understands user queries in several domains
(shown in the figure). It relies upon a large knowledge
base spanning multiple websites and its own
proprietary algorithms to provide users with detailed
answers to their questions on many different topics.
The results are displayed using a mix of multimedia,
including mathematical equations if appropriate.
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1.6.5 User Productivity
 Companies provide employees at all levels with technology that improves
productivity. Examples of user productivity systems include email, voice mail, video
and web conferencing, word processing, automated calendars, database
management, spreadsheets, desktop publishing, presentation graphics, company
intranets, and integrated mobile computing systems. User productivity systems also
include groupware. Groupware programs enable users to share data, collaborate
on projects, and work in teams.
 When companies first installed word processing systems, managers expected to
reduce the number of employees as office efficiency increased. That did not
happen, primarily because the basic nature of clerical work changed. With
computers performing the repetitive work, office personnel were able to handle
tasks that required more judgment, decision making, and access to information.
 Computer-based office work expanded rapidly as companies assigned more
responsibility to employees at lower organizational levels. Relatively inexpensive
hardware, powerful networks, corporate downsizing, and a move toward employee
empowerment also contributed to this trend.
 Today, administrative assistants and company presidents alike are networked, use
computer workstations, and share corporate data to perform their jobs.
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1.6.6 Systems Integration
 Most large companies require systems that combine transaction processing,
business support, knowledge management, and user productivity features.
For example, suppose an international customer makes a warranty claim. A
customer service representative enters the claim into a TP system, which
updates two other systems: a knowledge management system that tracks
product problems and warranty activity, and a quality control system with
decision support capabilities. A quality control engineer uses what-if analysis
to determine if the firm should make product design changes to reduce
warranty claims. In this example, a TP system is integrated with a knowledge
management system and a business support system with decision support
features.
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1.7 What Information do users need?
 Corporate organizational structure has changed
considerably in recent years. In an effort to increase
productivity, many companies reduced the number of
management levels and delegated responsibility to
operational personnel. Although modern organization
charts tend to be flatter, an organizational hierarchy still
exists in most firms.
 A typical organizational model identifies business
functions and organizational levels, as shown in Figure 11.
Within the functional areas, operational personnel report
to supervisors and team leaders.
 The next level includes middle managers and knowledge
workers, who, in turn, report to top managers. In a
corporate structure, the top managers report to a board
of directors elected by the company’s shareholders.
 A systems analyst must understand the company’s
organizational model to recognize who is responsible for
specific processes and decisions and to be aware of
what information is required by whom.
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Figure 11. A typical organizational model identifies
business functions and organizational levels.

1.8 Systems Development Tools
 In addition to understanding business operations, systems analysts must
know how to use a variety of techniques, such as modeling, prototyping,
and computer-aided systems engineering tools to plan, design, and
implement information systems. Systems analysts work with these tools in a
team environment, where input from users, managers, and IT staff
contributes to the system design.
1.8.1 Modeling
 Modeling produces a graphical representation of a concept or process
that systems developers can analyze, test, and modify. A systems analyst
can describe and simplify an information system by using a set of business,
data, object, network, and process models .
 A business model describes the information that a system must provide.
Analysts also create models to represent data, objects, networks, and other
system components. Although the models might appear to overlap, they
actually work together to describe the same environment from different
points of view.
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 System developers often use multipurpose charting tools such as Microsoft Visio
to display business related models. Visio is a popular tool that systems analysts
can use to create business process diagrams, flowcharts, organization charts,
network diagrams, floor plans, project timelines, and work flow diagrams,
among others.
 Figure 12 shows how to drag and drop various symbols from the left pane into
the drawing on the right, and connect them to show a business process. There
are similar online tools for drawing business-related models, such as draw.io.
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1.8.2 Prototyping
 Prototyping tests system concepts and provides an opportunity to examine
input, output, and user interfaces before final decisions are made. A
prototype is an early working version of an information system. Just as an
aircraft manufacturer tests a new design in a wind tunnel, systems analysts
construct and study information system prototypes. A prototype can serve
as an initial model that is used as a benchmark to evaluate the finished
system, or the prototype itself can develop into the final version of the
system. Either way, prototyping speeds up the development process
significantly.
 A possible disadvantage of prototyping is that important decisions might
be made too early, before business or IT issues are understood thoroughly.
A prototype based on careful fact-finding and modeling techniques,
however, can be an extremely valuable tool.
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1.8.3 Computer-aided systems engineering (Case) tools
 Computer-aided systems engineering (CASE), also called computer-aided software
engineering, is a technique that uses powerful software, called CASE tool, to help systems
analysts develop and maintain information systems. CASE tools provide an overall framework
for systems development and support a wide variety of design methodologies, including
structured analysis and object-oriented analysis.
 Because CASE tools make it easier to build an information system, they boost IT productivity
and improve the quality of the finished product.
 After developing a model, many CASE tools can generate program code, which speeds the
implementation process. Figure 13 shows the website for Visible Systems Corporation, a CASE
tool vendor.
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1.9 Systems Development Methods
 Many options exist for developing information systems, but the most popular
alternatives are structured analysis, which is a traditional method that still is
widely used, object-oriented (o-o) analysis, which is a more recent approach
that many analysts prefer, and agile methods, also called adaptive methods,
which include the latest trends in software development. Figure 14 provides an
overview of the three methods, which are discussed in the following sections.
 Although most projects utilize one approach, it is not unusual for system
developers to mix and match methods to gain a better perspective. In addition
to these three main development methods, some organizations choose to
develop their own in- house approaches or use techniques offered by software
suppliers, CASE tool vendors, or consultants. Many alternatives exist, and IT
experts agree that no single development method is best in all cases. An
approach that works well for one project might have disadvantages or risks in
another situation. The important thing is to understand the various methods and
the strengths and weaknesses of each approach.
 Regardless of the development strategy, people, tasks, timetables, and costs
must be managed effectively. Complex projects can involve dozens of people,
hundreds of tasks, and many thousands of dollars. Project management is the
process of planning, scheduling, monitoring, controlling, and reporting upon the
development of an information system.
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1.9.1 Structured Analysis
 Structured analysis is a traditional systems development technique that is time-
tested and easy to understand. Structured analysis uses a series of phases,
called the systems development life cycle (SDLC), to plan, analyze, design,
implement, and support an information system. Although structured analysis
evolved many years ago, it remains a popular systems development method.
Structured analysis is based on an overall plan, similar to a blueprint for
constructing a building, so it is called a predictive approach.
 Structured analysis uses a set of process models to describe a system
graphically. Because it focuses on processes that transform data into useful
information, structured analysis is called a process-centered technique. In
addition to modeling the processes, structured analysis also addresses data
organization and structure, relational database design, and user interface
issues.
 A process model shows the data that flows in and out of system processes.
Inside each process, input data is transformed by business rules that generate
the output. Figure 15 shows a process model that was created with the Visible
Analyst CASE tool. The model, which represents a school registration system, is
called a data flow diagram (DFD) because it uses various symbols and shapes
to represent data flow, processing, and storage.
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 Structured analysis uses the SDLC to plan and manage the systems
development process. The SDLC describes activities and functions that
all systems developers perform, regardless of which approach they
use. In the waterfall model, the result of each phase is called a
deliverable, which flows into the next phase.
 Some analysts see a disadvantage in the built-in structure of the SDLC,
because the waterfall model does not emphasize interactivity among
the phases. This criticism can be valid if the SDLC phases are followed
too rigidly.
 However, adjacent phases can and do interact, as shown by the
circular arrows in Figure 17, and interaction among several phases is
not uncommon. Used in this manner, the traditional model is not as
different from Agile methods as it might appear to be.
 The SDLC model usually includes five steps, which are described in the
following sections: systems planning, systems analysis, systems design,
systems implementation, and systems support and security.
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1.9.2 Object-Oriented Analysis
 Whereas structured analysis treats processes and data as separate components, object-
oriented analysis combines data and the processes that act on the data into things called
objects. Systems analysts use O-O to model real-world business processes and operations.
The result is a set of software objects that represent actual people, things, transactions, and
events. Using an O-O programming language, a programmer then writes the code that
creates the objects.
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O-O analysis uses object models to represent data and behavior,
and to show how objects affect other objects. By describing the
objects and methods needed to support a business operation, a
system developer can design reusable components that speed
up system implementation and reduce development cost.
Object-oriented methods usually follow a series of analysis and
design phases that are similar to the SDLC, although there is less
agreement on the number of phases and their names. In an O-O
model, the phases tend to be more interactive. Figure 19 shows
an O-O development model where planning, analysis, and
design tasks interact to produce prototypes that can be tested
and implemented.
The result is an interactive model that can actually depict real-
world business processes. O-O methodology is popular because
it provides an easy transition to O-O programming languages
such as C++, Java, and Swift.

1.9.3 Agile Methods
 Development techniques change over time. For example, structured analysis is a
traditional approach, and agile methods are the newest development. Structured
analysis builds an overall plan for the information system, just as a contractor might
use a blueprint for constructing a building. Agile methods, in contrast, attempt to
develop a system incrementally, by building a series of prototypes and constantly
adjusting them to user requirements. As the agile process continues, developers
revise, extend, and merge earlier versions into the final product. An agile approach
emphasizes continuous feedback, and each incremental step is affected by what
was learned in the prior steps.
 Although relatively new to software development, the notion of iterative
development can be traced back to Japanese auto firms that were able to boost
productivity by using a flexible manufacturing system, where team-based effort and
short-term milestones helped keep quality up and costs down. Agile methods have
attracted a wide following and an entire community of users (Agile Alliance).
 Agile methods typically use a spiral model, which represents a series of iterations, or
revisions, based on user feedback. As the process continues, the final product
gradually evolves. An agile approach requires intense interactivity between
developers and individual users, and does not begin with an overall objective.
Instead, the agile process determines the end result. Proponents of the spiral model
believe that this approach reduces risks and speeds up software development.
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 Barry Boehm, a noted software engineering professor, initially suggested spiral
models in the 1990s. He stated that each iteration, or phase, of the model must
have a specific goal that is accepted, rejected, or changed by the user or client.
Thus, each iteration produces feedback and enhancements, which enable the
team to reach the overall project goal. Typically, each iteration in a spiral model
includes planning, risk analysis, engineering, and evaluation. The repeated
iterations produce a series of prototypes, which evolve into the finished system.
Notice that these phases resemble SDLC tasks, which also can be iterative.
 Numerous other adaptive variations and related methods exist, and most IT
developers expect this trend to continue in the future. Two examples are Scrum,
and Extreme Programming (XP).
 Although agile methods are becoming popular, analysts should recognize that
these approaches have advantages and disadvantages. By their nature, agile
methods can allow developers to be much more flexible and responsive, but can
be riskier than more traditional methods. For example, without a detailed set of
system requirements, certain features requested by some users might not be
consistent with the company’s larger game plan.
 Other potential disadvantages of agile methods can include weak
documentation, blurred lines of accountability, and too little emphasis on the larger
business picture. Also, unless properly implemented, a long series of iterations might
actually add to project cost and development time. The bottom line is that systems
analysts should understand the pros and cons of any approach before selecting a
development method for a specific project.
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1.9.4 Other Development Methods
 IT professionals know that the key to success is user input—before, during,
and after a system is developed. Over time, many companies discovered
that systems development teams composed of IT staff, users, and managers
could complete their work more rapidly and produce better results. Two
methodologies became popular: joint application development (JAD) and
rapid application development (RAD).
 Both JAD and RAD use teams composed of users, managers, and IT staff.
The difference is that JAD focuses on team-based fact-finding, which is only
one phase of the development process, whereas RAD is more like a
compressed version of the entire process.
 Companies often choose to follow their own methodology. Using CASE
tools, an IT team can apply a variety of techniques rather than being bound
to a single, rigid methodology. Regardless of the development model, it will
be necessary to manage people, tasks, timetables, and expenses by using
various project management tools and techniques.
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1.11 The Systems Analyst
 A systems analyst investigates, analyzes, designs, develops, installs, evaluates, and
maintains a company’s information systems. To perform those tasks, a systems
analyst constantly interacts with users and managers within and outside the
company. The following sections describe a system analyst’s role, knowledge, skills,
education, certifications, and career opportunities.
1.12 Trends in Information Technology
 Very few areas evolve as fast as information technology. Each year sees
evolutionary developments in current technology, such as faster processors, wider
network bandwidth, and increased storage capabilities. Once in a while a truly
transformative change occurs, such as the ongoing shift to cloud computing
across the enterprise, or a revolution in the basic tenets of computation with the
nascent introduction of quantum computing.
 Systems analysts should be aware of current trends in information technology, so
that they can better serve their organizations and so that they can adapt their skill
sets going forward.
 Some of the key trends that are disrupting information technology include agile
methods, cloud computing, mobile devices, service orientation, and social media
networks.
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