کۆرسی یەکەم دەیخوێنین lectures(2)

1. SYSTEMS ANALYSIS
& DESIGN
lectures
2017-2018
By: Assistant Lecturer
Zhiyan A. younis

2. THE IMPACT OF INFORMATION
TECHNOLOGY
Information technology (IT) refers to the combination of hardware, software, and
services that people use to manage, communicate, and share information. Although
the huge impact of IT on our society. More than ever, business success depends on
information technology. IT is driving a new digital economy, where advances in
hardware, software, and connectivity can provide enormous benefits to businesses and
individuals. Although economic trends affect IT spending levels, most firms give IT
budgets a high priority, in good times or bad(why?). The reason is simple — during
periods of growth, companies cannot afford to lag behind the IT curve. Conversely,
when the economy slows down, firms often use IT to reduce operating costs and
improve efficiency.
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3. The Future
If you ask a group of IT professionals to name a
company that has been successful for over 100
years, the answer probably would be IBM. As its
name suggests, International Business Machines
was a major supplier of typewriters and data
processing equipment long before the computer
era.
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4. UNDERSTAND THE BUSINESS
IT professionals must understand a company’s
operations to design successful systems. Each
business situation is different. Systems analysts use
a process called business process modeling to
represent company operations and information
needs. Business process modeling requires a
1-business profile
2-a series of models that document business
processes.
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5. Business Profile
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 fact-finding. A
business profile is the starting point for the
modeling process.
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6. Business Process
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.
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7. The example in the below Figure shows a simple model
that includes an event, three processes, and a result.
Process:
Verify Customer Credit
Process:
Check Customer Status
Process:
Enter Customer Order
Data
Event:
Receive Sales Order
Result:
Completed Sales Order
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8. business process modeling notation
(BPMN)
A rough sketch might be sufficient to document a simple business process. For
complex operations, however, analysts apply computer-based modeling tools that use
a standard language called business process modeling notation (BPMN). BPMN
includes various shapes and symbols to represent events, processes, and
workflows, as shown in the example in the next Figure. Modeling tools include
multi-purpose graphical applications, such as Microsoft Visio, and computer-aided
software engineering programs such as Visible Analyst
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9. This sample uses business process modeling notation
(BPMN) to represent events, processes,
and workflow.
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10. IMPACT OF THE INTERNET
The newest kind of company is the Internet-dependent firm,
often described as adot-com (.com) company because its
primary business depends on the Internet rather than a
traditional business channel. Google, Yahoo!, Amazon, and
eBay are examples of pure dot-com companies.
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11. IMPACT OF THE INTERNET
Internet-based commerce is called e-commerce (electronic commerce)
or I-commerce (Internet commerce). Internet-based systems involve
various hardware and software designs, but a typical model is a series
of Web pages that provides a user interface, which communicates with
database management software and a Web-based data server. As Internet-
based commerce continues to grow, career opportunities will expand
significantly for IT Professionals such as Web designers, database
developers, and systems analysts.
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12. 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& security 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.
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13. 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.
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14. Types of modeling
• A business model, or requirements model, describes
the information that a system must provide.
• A data model describes data structures and design.
• An object model describes objects, which combine
data and processes.
• A network model describes the design and protocols
of telecommunications links.
• A process model describes the logic that programmers
use to write code modules.
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15. Prototyping
Prototyping tests system concepts and
provides an opportunity to examine input,
output, and user interfaces before final
decisions are made.
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16. 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 tools, 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.
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17. SYSTEMS DEVELOPMENT
METHODS
the most popular alternatives are
1- structured analysis, which is a traditional method that still is widely used.
Structured analysis uses a series of phases, called the systems development
life cycle (SDLC), to:
• plan(which describes problems or desired changes in an information system or a
business process.),
• Analyze(to build a logical model of the new system.)
• design(to create a physical model that will satisfy all documented requirements
for the system.)
• implement(the new system is constructed)
• support &security(the IT staff maintains, enhances, and protects the
system)
• 2- object-oriented (O-O) nalysis (combines data and the processes that act
on the data into things called objects)
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18. THE INFORMATION
TECHNOLOGY DEPARTMENT
The IT department develops and maintains
information systems. The structure of the IT
department varies among companies
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19. 19 1953

20. THE SYSTEMS ANALYST
The systems analyst’s job overlaps business and
technical issues. Analysts help translate
business requirements into IT projects. When
assigned to a systems development team,
an analyst might help document business profiles,
review business processes, select hardware and
software packages, design information systems,
train users, and plan e-commerce Web sites.
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