2. Phase Description
• Systems Design is the third of five phases in
the systems development life cycle
• Now you will work on a physical design that
will meet the specifications described in the
system requirements document
• Tasks will include user interface design, data
design, and system architecture
• Deliverable is system design specification
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3. Chapter Objectives
• Explain the concept of user interface design
and human-computer interaction, including
basic principles of user-centered design
• List user interface design guidelines
• Describe user interface components, including
screen elements and controls
• Discuss output design and technology issues
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4. Chapter Objectives
• Design effective source documents
• Explain input design and technology issues
• Discuss guidelines for data entry screen design
• Use input masks and validation rules to reduce
input errors
• Describe output and input controls and
security
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5. Introduction
• User interface design is the first task in the
systems design phase of the SDLC
• Designing the interface is extremely
important, because everyone wants a system
that is easy to learn and use
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6. What Is a User Interface?
• User interface (UI) describes how users
interact with a computer system,
• Consists of all the hardware, software,
screens, menus, functions, outputs, and
features that affect two-way communications
between the user and the computer
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7. User Interface Design
• User Interface Design is the design of
websites, computers, machines, mobile
communication devices, and software
applications with the focus on the user’s
experience and interaction.
• The goal of user interface design is to make
the user’s interaction as simple and efficient
as possible, in terms of accomplishing user
goals—what is often called user-centered
design. 7
9. User Interface Design
• Human-Computer Interaction
– Human-computer interaction (HCI) describes the
relationship between computers and people who
use them to perform their jobs
– HCI started in the 1980s with users typing complex
commands in green text on a black screen.
– Graphical user interface (GUI) used icons,
graphical objects, and pointing devices.
– Main objective is to create a user-friendly design
that is easy to learn and use
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10. Principles of User-Centered Design
• Although IT professionals have different views about
interface design, most would agree that good design
depends on seven basic principles,
– Understand the Business
– Maximize Graphical Effectiveness
– Think Like a User
– Use Models and Prototypes
– Focus on Usability
– Invite Feedback
– Document Everything 10
11. Designing the User Interface
• It is important to design a user interface that is easy
to use, attractive, and efficient. Follow eight basic
guidelines
1. Design a transparent interface
2. Create an interface that is easy to learn and use
3. Enhance user productivity
4. Make it easy for users to obtain help or correct
errors
5. Minimize input data problems
6. Provide feedback to users
7. Create an attractive layout and design
8. Use familiar terms and images 11
12. Output Design
• Before designing output, ask yourself several
questions:
– What is the purpose of the output?
– Who wants the information, why is it needed, and
how will it be used?
– What specific information will be included?
– Will the output be printed, viewed on-screen, or
both? What type of device will the output go to?
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13. Output Design
• Before designing output, ask yourself several
questions:
– When will the information be provided, and how
often must it be updated?
– Do security or confidentiality issues exist?
• Your answers will affect your output design
strategies
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14. Output Design
• Types of Reports
– Detail reports
• A detail report produces one or more lines of output for each
record processed. Each line of output printed is called a detail line.
– Exception reports
• An exception report displays only those records that meet a
specific condition or conditions. It is useful when the user wants
information only on records that might require action, but does
not need to know the details.
– Summary reports
• Upper-level managers often want to see total figures and do not
need supporting details.
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15. Output Design
• User Involvement in Report Design
– Printed reports are an important way of delivering
information, so users should approve all report
designs in advance.
– The best approach is to submit each design for
approval as you complete it, rather than waiting
until you finish all report designs.
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17. Input Design
• The best time to avoid problems is when the
data is entered.
• The quality of the output is only as good as
the quality of the input
– Garbage in, garbage out (GIGO)
– Objective of input design is to ensure the quality,
accuracy, and timeliness of input data
– Good input design requires attention to human
factors as well as technology issues
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18. Input Design
• During input design, you determine how data
will be captured and entered into the system.
– Guidelines
1. Restrict user access to screen locations where data is entered
2. Provide a descriptive caption for every field, and show the user
where to enter the data and the required or maximum field
size
3. Display a sample format if a user must enter values in a field in
a specific format
4. Display a list of acceptable values for fields, and provide
meaningful error messages
5. Provide users with an opportunity to confirm the accuracy of
input data before entering it
6. Allow users to add, change, delete, and view records
7. Provide a method to allow users to search for specific
information 18
19. Input Design
• Input Masks
– Use input masks, which are templates or patterns
that restrict data entry and prevent errors
– A mask can manipulate the input data and apply a
specific format
– if a user enters text in lowercase letters, the input
mask Will automatically capitalize the first letter.
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20. Input Design
• Validation Rules
– Reducing the number of input errors improves
data quality. One way to reduce input errors is to
eliminate unnecessary data entry.
– At least seven types of data validation rules
1. Sequence check
2. Existence check
3. Data type check
4. Range check – limit check
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5. Reasonableness check
6. Validity check –
referential integrity
7. Combination check
21. Input Design
• Input Volume Reduction
– To reduce input volume, you must reduce the
number of data items required for each
transaction.
– Guidelines will help reduce input volume
1. Input necessary data only
2. Do not input data that the user can retrieve from
system files or calculate from other data
3. Do not input constant data
4. Use codes
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22. Security and Control Issues
• A company must do everything in its power to
protect its data. This includes not only the
firm’s own information, but that of its
customers, employees, and suppliers.
• Most assets have a value, but corporate data
is priceless, because without safe, secure,
accurate data, a company cannot function.
– Output security
• Output must be accurate, complete, current, and
secure.
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23. Security and Control Issues
• Input Security and Control
– Input control includes the necessary measures to
ensure that input data is correct, complete, and
secure.
– You must focus on input control during every
phase of input design, starting with source
documents that promote data accuracy and
quality.
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