CIS 302 Introduction to Systems Analysis and Design

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					       CIS 302 Introduction to
       Systems Analysis and
               Design

             Input Design




14.1
          Chapter 7

Input Design
            Objectives
Discuss the objectives of systems input
design
Explain the differences among data capture,
data entry, and data input
Explain the differences between batch and
online input
List and describe the different types of data
validation checks
Discuss effective source document design
          Objectives
Design input records
Discuss guidelines for effective screen
design
Describe and design data entry
screens, process control screens,
graphical user interfaces, and Help
screens
Explain input control techniques
            Introduction
Input technology has changed greatly
Output quality depends on input quality
Main objectives of input design
   User-friendly interface
   Input processes that ensure data quality,
    accuracy and timeliness



                              Click to see Figure 7-1
    Input Design Objectives
Definitions
   Data capture
      Identification and recording of source data
   Data entry
      Conversion of source data into a computer-
      readable form
   Data input
      Process by which the computer-readable source
      data enters the information system
     Input Design Objectives
Four main input design objectives
1.   Select input media and methods
2.   Develop efficient input procedures
3.   Reduce input volume
4.   Reduce input errors
    Input Design Objectives
Input media and data entry methods
   Batch input method
      Data entry is done over period of time
      Collection (batch) of data is input at one time
   Online data entry method
      Also called direct data entry
      Data is validated and available immediately
    Input Design Objectives
Input media and data input methods
   Source data automation
     Combines online data entry with online data
      capture
     Uses magnetic data strips and swipe scanners
     Common examples: ATMS, point-of-sale
      terminals, bar code readers, patient ID bracelets,
      libraries
    Input Design Objectives
Develop efficient input procedures
   Procedures
     Must be efficient, timely, and logical
     Must identify potential bottlenecks
    Input Design Objectives
Reduce input volume
   Less volume means less time, effort, and
    cost
   Four guidelines
     1. Input necessary data only
     2. Do not input data that can be retrieved from
       system files or calculated from other data
     3. Do not input constant data
     4. Use codes
            TRADEOFF
Should users ever enter retrievable data for
verification purposes?
  Online data entry allows immediate verification,

   but batch input methods do not
  Batch input data can be verified by entering a

   second data item, such as a customer name in
   addition to a customer number, which must match
   a specific record when the data is input
  Pros and cons: this method can detect invalid

   entries, but involves more time and expense
       A KEY QUESTION
Should Prowler Products change to an
online data entry system?
   Pros: improved data accuracy, customer
    satisfaction, and company image
   Cons: more expensive
Are these valid reasons to change?
What cost-benefit issues should be
analyzed?
What factors should be considered?
    Input Design Objectives
Reduce input errors
   Fewer errors mean better data quality
   Eight types of data validation checks
     1.   Sequence checks
     2.   Existence checks
     3.   Data type checks
     4.   Range checks
     5.   Reasonableness checks
     6.   Validity checks
     7.   Combination checks
     8.   Batch controls
 Key Tasks in Input Design
Six key tasks
1. Design data entry and input procedures
2. Design source documents for data capture,
  or devise other data capture methods
3. Design input data records
4. Design data entry screens
5. Design user interface screens
6. Design audit trails and system security
  measures
 Source Document Design
Source documents
   Request and collect input data
   Can trigger or authorize input actions
   Provide a record of the original transaction
Form layout guidelines
   Allow sufficient space
   Offer clear instructions
   Provide logical organization
   Use captions effectively
Source Document Design
Form zones
   Heading zone
   Control zone
   Instruction zone
   Totals zone
   Authorization zone
Source documents can be external or
internal
      Input Record Design
Input record layout chart
   To design and document batch input records
   Multiple record designs are used for
    transactions that involve constant and
    repeating data
      Constant fields (non-repeating data)
      Repeating fields
       Input Record Design
Information flow on a form
   Should be logical and easy to follow
       Input Record Design
Information flow on a form
   Should be logical and easy to follow
   Poor design results in forms that are difficult
    to use, time-consuming, and prone to error
        Screen Design
Effective screen design guidelines
1. Screens should be attractive and
  uncluttered
2. Information on a single screen should be
  displayed in a meaningful, logical order
3. Screen designs should be consistent
4. Messages should be specific,
  understandable, and professional
5. Messages should remain on the screen for
  an appropriate period of time
        Screen Design
Effective screen design guidelines
6. Special effects should be used sparingly
7. Users should receive feedback
8. Screen designs should be documented and
  approved as soon as possible
            Screen Design
Data entry screen design
   Guidelines
     1. Restrict user access to screen locations where
       data is entered
     2. Provide a descriptive caption for each field and
       show the user where to enter the data
     3. Show a sample format if one is required
     4. Require ending keystroke for every field
     5. Do not require users to enter special characters
         Screen Design
   Guidelines
    6. Do not require users to type leading zeroes or
        trailing spaces for alphanumeric fields
    7. Do not require users to type trailing zeroes that
        follow a decimal point
    8. Display default values that users can accept
    9. Use default values for constant data
    10. Display a list of acceptable values for fields
        with a limited number of valid choices
          Screen Design
1.   Guidelines
     11. Provide a way to leave the data entry screen
         without inputting the current record
     12. Provide an opportunity to confirm the
         accuracy of input data before entering it
     13. Provide a means to move among form fields
         in a standard, or in another, order
     14. Design the screen form to match the layout
         of the source document
          Screen Design
2.   Guidelines
     15. Allow the operator to add, change, delete,
         and view records
     16. Design a method to allow operators to
         search for a specific record
               TRADEOFF
2. When should input data be validated? Is it better to
  check the values as soon as each value is entered,
  or wait until all fields are input? What issues should
  be considered?
   2. What type of field is involved, and does it affect

      other fields?
   3. Can data be validated at time of entry?

   4. Can missing data be obtained later?

   5. Which method do users prefer?
    A KEY QUESTION
At Boolean Toys, should individual
users be allowed to select data entry
and validation methods, or should a
standard method be required?
What are the pros and cons of allowing
different validation methods in the same
system?
               Screen Design
4.Process control screen design
  4.   Users can control system actions with
       interactive menus and prompts
  5.   Menu screens
        4.Menus display a list of user-selectable options
            Screen Design
Process control screen design
   Users can control system actions with
    interactive menus and prompts
   Menu screens
      Menus display a list of user-selectable options
      Menu-driven system uses a hierarchy of main
       menus and submenus
      Shortcut key combinations can be used in a
       menu design
           Screen Design
Process control screen design
   Prompt screens
     User types a response to a prompt
           Screen Design
Process control screen design
   Prompt screens
     User types a response to a prompt
     Responses can include commands
            Screen Design
Process control screen design
   Prompt screens
     User types a response to a prompt
     Responses can include commands
     Structured Query Language (SQL) can be used
     Question/answer screens can be used
     Natural language techniques can be used,
      similar to Internet search engines




                                    Click to see Figure 7-22
            Screen Design
Process control screen design
   Combination screens
     Menus and prompt screens can be combined
      effectively
            Screen Design
Graphical user interfaces
   A GUI environment includes process control
    and data control
   A GUI environment is easy to use
   Common features
      Menu bar
      Toolbar
           Screen Design
   Common features
     Menu bar
     Toolbar
     Drop-down menus
           Screen Design
   Common features
     Menu bar
     Toolbar
     Drop-down menus
     Dialog, text, and drop-down list boxes
           Screen Design
   Common features
     Menu bar
     Toolbar
     Drop-down menus
     Dialog, text, and drop-down list boxes
     Option (radio) buttons
           Screen Design
   Common features
     Menu bar
     Toolbar
     Drop-down menus
     Dialog, text, and drop-down list boxes
     Option (radio) buttons
     Spin bars
            Screen Design
Help screen design
   Several methods to obtain Help
      Click a command button or toolbar
      Press a special key
   Context-sensitive Help
      Provides Help on the task in progress
             Screen Design
Help screen design
   Several methods to obtain Help
      Click a command button or toolbar
      Press a special key
   Context-sensitive Help
      Provides Help on the task in progress
   User-selected Help
   Hypertext
      Uses links to display additional information on
      related topics
             Screen Design
   Design guidelines
      Provide a direct route for users to return to the
       program after Help is obtained
      Title every Help screen
      Use easy, simple, understandable Help text
      Present attractive, uncluttered screens
      Provide appropriate examples
      Use hyperlinks
      Include contact data for persons or departments
       responsible for assisting users
             Input Control
Measures to ensure that data is correct, complete, and
secure
  Effective source document design

  Data validity checks

  Batch input controls

  Log files for rejected records

  Audit trails

  Data security measures, including encryption

  Password and sign-on procedures

  Records retention policies

				
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posted:12/4/2011
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