Understand the Business Function
ACS 367
Step #2
Business Function
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Perform business definition and requirements analysis
Determine basic business functions
Describe current activities through task analysis
Develop a conceptual model of the system
Establish design standards or style guides
Establish system usability design goals
Define training and documentation needs
business definition and requirements
analysis
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Establish the need for a system
Determine requirements
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Direct Methods
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Observational study, prototyping, usability labs
Indirect Methods
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MIS intermediary, Surveys…
Determining Basic
Business Function
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A detailed description of what the
product will do is prepared.
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Major system functions are described (IPO)
A flowchart of major functions is developed
Task Analysis
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Task analysis involves breaking down user’s
activities to the individual task level.
The goal is to obtain an understanding of
why and how people currently do the things
that will be automated.
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Knowing WHY: establishes the work goals
Knowing HOW: provides details of actions
performed to accomplish the goals.
Task Analysis
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Task analysis provides information
concerning:
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Work flows
Interrelationships between people
Objects
Acionts
The output of a task analysis is a complete
description of all user tasks and interactions.
Task Analysis
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A goal of task analysis and a goal of
understanding the user, is to gain a
picture of the user’s mental model.
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A mental model is an internal
representation of a person’s current
conceptualization and understanding of
something.
Mental Models
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Guidelines for designing mental models
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Reflect the user’s mental model not the
designer’s
Draw analogies or present metaphors
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Success of desktop metaphor
Comply with expectancies, habits, routines
and stereotypes
Design Standards or
Style Guides
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Value of standards (users)
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Faster performance
Fewer errors
Reduced training time
Better satisfaction
Better system acceptance
Design Standards or
Style Guides
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Value of standards (designers)
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Increased visibility to HCI
Simplified Design
Reduced redundant effort
Reduced training
Design Standards or
Style Guides
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Document Design
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Include many concrete examples of concrete
design
Provide rationale describing conditions under
which various design alternatives are appropriate
Provide good access
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Table of contents
Index
checklists
Design Standards or
Style Guides
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Examples (ISU iGuide)
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http://www.iwss.ilstu.edu/iguide/
Usability Goals
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Usability (Bennett, 1979)
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The capacity to be used by humans easily
and effectively, where
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Easily:
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to a specified level of subjective assesment
Effectively:
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To a specified level of human performance
Common Usability Problems
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Ambiguous menus and icons
Unclear step sequences
More steps to manage interface that to
do tasks.
Inadequate feedback and confirmation
Measures of Usability
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Are people asking a lot of questions?
Are frequent exasperation responses
heard?
Are there many irrelevant actions being
performed?
Are there many things to ignore?
Do a number of people want to use a
product?
Criteria for Measuring Usability
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Effectiveness
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Learnability
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Within some specified time (learning curve)
Flexibility
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Level of performance
Be specific here (required percentage)
Allowing adaptation to some specified percentage
variation in tasks
Attitude
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Levels of tiredness, discomfort, frustration…