chapter 11 designing the system output. sad/chapter 112 learning objectives understand the process...
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Chapter 11
Designing the System Output
SAD/CHAPTER 11 2
Learning Objectives Understand the process of
designing high quality and effective system output
Identify the basic characteristics of high quality system output
Discuss control strategies for system output
SAD/CHAPTER 11 3
Learning Objectives Identify and discuss the various
categories of output, media, and output technology
Understand ways in which unintentional bias can be introduced into system output
Identify and discuss available backup and retention strategies for data recovery
SAD/CHAPTER 11 4
Introduction Users of an IS need output to
accomplish their assigned tasks. The overall satisfaction with a
system is often measured by the quality of its output.
SAD/CHAPTER 11 5
Designing System Output Objective of Output
To create output that presents the desired information to the end user in an understandable and usable fashion
SAD/CHAPTER 11 6
Output Characteristics Purpose
What is the intended use or purpose of the output?
The purpose of the output may dictate the order or sequence of the various data elements contained within it.
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Output Characteristics Recipient
Who will be the primary users of the output?
The intended recipients of the output should be involved in the design and approval of each system output relevant to their assigned tasks.
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Output Characteristics Frequency
How often will the output need to be generated?
Minimizing the time between the request for the output and the receipt of the output
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Output Characteristics Distribution
Where will the output be used? Output distribution is becoming less
important due to the increased sophistication of client-server environments and local computer peripherals.
SAD/CHAPTER 11 10
Output Characteristics Human-machine Boundary
The point where an end user interacts with the system through the exchange of data or information
SAD/CHAPTER 11 11
Figure 11-1. Human – Machine Boundary for Employee Payroll System
1.0
CreateWeeklyPayrollRecord
Employee Data FileS1Employee
Employee Tax Form
Payroll Data FileS2
AccountingDepartment
2.1
ComputeGross
Pay
2.3
CreatePayrollCheck
2.2
ComputeNetPay
3.2
PrintWeeklyPayroll
Summary
3.1
SortPayroll
Records by
Employee
4.2
PrintEmployee
TaxForm
4.1
CalculatePayroll
Deductions
Employee Paycheck
PayrollDeductions
Employee PayrollRecord
Time Sheet
Employee Record
Gross PayData
Net PayData
Hours Worked
Payroll Record
Sorted Records
Payroll Report
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Output Characteristics Data Sources
What information must be delivered by the output?
No source data, no output
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Output Characteristics Media
In what form will the output be delivered?
If a given output must be generated using more than one primary media, additional design constraints may be encountered.
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Output Characteristics Format
How will the content of the output be displayed and formatted?
Tabular Zoned Narrative Graphical
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Figure 11-2. Combination Approach to Screen-Based Output
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Output Characteristics Control
What controls are necessary to limit access to the output?
Distributed control Division of labor Completeness control
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Output Design Issue
Description
Purpose What is the intended use or purpose of the output?
Primary User(s)
Who will be the primary users of the output?
Frequency How often will the output need to be generated?
Delivery Point Where will the output be used?
Human-Machine Boundaries
What are the points in the system where the end user must (or can) interact with the system?
Content What information must be delivered by the output?
Media In what form will the output be delivered?
Format How will the content of the output be displayed and formatted?
Controls What controls are necessary to limit access to the output?
Table 11-1. Output Design Issues to be Addressed
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Output Guideline Explanation Clear and meaningful titles Titles should clearly and specifically describe the content and use of
the output.
Relevant content Only the information necessary to use the output should be included and the presentation should be such that the output can be used without modification.
Balanced Layout Adequate spacing and margining should be used to allow for a balanced or symmetrical presentation of the output.
Clear Navigation The output should make navigation and location easy for the end user. This includes the use of indicators such as page numbers, section numbers, and end of section or sequence indicators.
Use of highlighting and color Techniques for emphasizing a particular data value, exception, or section should be used to make it easier for the end user to focus on important items contained within the output. Such techniques include color or intensity differences, multiple size fonts, underlining, bolding or italicizing, and capitalization.
Appropriate formatting of text elements
Text should be presented using mixed upper and lower case with conventional punctuation. Paragraphs should be double-spaced or separated by a blank line when single-spaced. Abbreviation and acronyms should be commonly understood or clearly defined on first use. Words should not be hyphenated between lines.
Appropriate formatting of tabular elements
All columns and rows should be clearly and meaningfully labeled. All labels should be repeated when data extends beyond a single page or screen. Columns and rows should be sorted in a meaningful order. All numerical data should be right-justified with decimal points aligned and all text data should be left-justified using relatively short line lengths (30 to 40 characters).
Table 11-2. Common Design Guidelines for Output
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Date and time stamp of output generation Data and time stamp for data or information
contained in the output Time period covered by output contents Distribution or routing list Cover sheet with output version number and
date Output header identification and description Clear pagination using “page __ of __” format Control totals where appropriate End of output trailer or indicator
Table 11-3. Common Completeness Controls for System Output
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Types of Output External Output
Leave the boundary of the system and serve to either confirm a system action to the recipient or to trigger an action on the part of a recipient
Turnaround Document
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Types of Output Internal Output
Output that normally stays within the system boundary and is used to support the organizational responsibilities and activities of the end users
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Internal output Detail Report
To present data or information with only a minimum amount of filtering
Historical lists of transactions A list of customers sorted by zip code A list of paychecks for a given period
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Internal output Summary report
To allow users to review information in a filtered or categorized form
Month-to-date or year-to-date sales by product category
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Internal output Exception report
An internal output that contains filtered information intended to report events or transactions that require special attention
Overdue customer accounts A list of items reach reorder point
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Media Type and Output Technology
Hard Copy Still the most common output media Impact technology Non-impact technology
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Media Type and Output Technology
Screen Output Can be viewed from any location Offers real-time editing and
modification Reduces storage costs Does not require long-term storage
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Media Type and Output Technology
Audio and Video Output Rich in the communication of
information Provides high quality interaction with
users and customers Speech synthesis and recognition
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Figure 11-4. Screenshot from Video Editing Software
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Media Type and Output Technology
COM Output Computer output microfilm or
microfiche Decreasing in popularity due to
advancement in digital scanning and storage technologies
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Media Type and Output Technology
Robotic Output Used as a vehicle for complex output
intended to automate production, manufacturing, distribution, and applications requiring precise handling of physical component
Microsurgery and minimally invasive surgery
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Figure 11-5. Robotic Output Devices
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Output Technology Output Media
Printer – impact, page, laser, inkjet, thermal, plotter
Paper, transparency
Computer Monitor –CRT, LCD, Plasma
Screen
COM Microfilm, microfiche
Voice Synthesis Voice synthesizer
Robotic Mechanical robotic devices
Video Screen, film, disk, CD-ROM, DVD
Table 11-4. Common Output Media and Technologies
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Output Bias Issues Range or Value Limits Sorting or Sequence Graphics
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Output Bias Issues Range and Value Limits
Inappropriate limits on displayed values Can introduce inaccuracies in
information contained in the output. Ranges that are set too low, too high, too
narrow, or too wide Can result in exception reports that are
either of little use or introduce unnecessary biases into the decision process.
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Output Bias Issues Sorting and Sequence Bias
Common methods Alphabetical Chronological Size Cost
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Figure 11-6. Example of Graphical Scaling Bias
0
5
10
15
20
25
30
35
North South East West
Car A
Car B
Car C
10
15
20
25
30
35
North South East West
Car A
Car B
Car C
6a.
6b.
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Output Bias Issues Graphical Bias
Inappropriate scaling can introduce an unintended bias into graphical information.
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Backup and Recovery Back files of an IS are internal
outputs, too. 50 percent of end users suffer
some form of data loss each year. Over half of the world's
commercial enterprise with no backup procedures could go bankrupt with 6 months following a catastrophic loss of data.
SAD/CHAPTER 11 39
Cost of Data Loss $50,000 per Mb to re-create $18,000 per hour in downtime cost for PC
LANs $75,000 per hour in downtime cost for
UNIX network $17,000 to re-create 20 Mb of sales and
marketing data $19,000 to re-create 20 Mb of account data $98,000 to re-create 20 Mb of engineering
data
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Backup and Recovery Disaster recovery Plan
A comprehensive statement of consistent actions to be taken before, during, and after a disaster
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Data Backup and Retention Strategies
Incremental backup Establish a repetitive cycle that
begins with a full backup of all data files and continues through a series of incremental backups
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Monday Tuesday Wednesday Thursday Friday
Full backup Incremental backup
Incremental backup
Incremental backup
Incremental backup
All files, data, and applications
What has changed since Monday
What has changed since Tuesday
What has changed since Wednesday
What has changed since Thursday
Table 11-5. Incremental Data Backup Strategy
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Data Backup and Retention Strategies
Differential backup A variation of the incremental backup Based on the backup of all modified
files since the previous full backup
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Data Backup and Retention Strategies
Generational backup Use a system of tape rotation via
three storage sets. Set One: “grandfather” Set Two: “father” Set Three: “son”
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Friday Monday Tuesday Wednesday Thursday
Storage Set A (week 1)
Full
backup
Incremental
backup
Incremental
backup
Incremental
backup
Incremental
backup
Storage Set B (week 2)
Full
backup
Incremental
backup
Incremental
backup
Incremental
backup
Incremental
backup
Storage Set C (week 3)
Full
backup
Incremental
backup
Incremental
backup
Incremental
backup
Incremental
backup
Storage Set A (week 4)
Full
backup
Incremental
backup
Incremental
backup
Incremental
backup
Incremental
backup
… … … … … …
Table 11-6. Generation Data Backup and Retention Strategy
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Data Backup and Retention Strategies On-line backup system
Procedure Automatically detect files on an organization’s
computer network requiring backup. Encrypt those files for security. Compress the encrypted files. Transmit the data through high-speed network.
The amount of work to fully protect the data is greatly reduced.
- End -
SAD/CHAPTER 11 47
Chapter Summary The goal of IS is to deliver high
quality and relevant information to the end users of the system.
The specification of the complete scope of the outputs for a system is critical.
Chapter 11
End of Chapter