Understand the Business Function

ACS 367Step #2

Business Function 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

Establish the need for a system Determine requirements

Direct Methods Observational study, prototyping,

usability labs Indirect Methods

MIS intermediary, Surveys…

Determining Basic Business Function A detailed description of what the

product will do is prepared. Major system functions are described

(IPO) A flowchart of major functions is

developed

Task Analysis 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. Knowing WHY: establishes the work goals Knowing HOW: provides details of actions

performed to accomplish the goals.

Task Analysis Task analysis provides information

concerning: 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 A goal of task analysis and a goal

of understanding the user, is to gain a picture of the user’s mental model. A mental model is an internal

representation of a person’s current conceptualization and understanding of something.

Mental Models Guidelines for designing mental

models Reflect the user’s mental model not

the designer’s Draw analogies or present metaphors

Success of desktop metaphor Comply with expectancies, habits,

routines and stereotypes

Design Standards or Style Guides Value of standards (users)

Faster performance Fewer errors Reduced training time Better satisfaction Better system acceptance

Design Standards or Style Guides Value of standards (designers)

Increased visibility to HCI Simplified Design Reduced redundant effort Reduced training

Design Standards or Style Guides Document Design

Include many concrete examples of concrete design

Provide rationale describing conditions under which various design alternatives are appropriate

Provide good access Table of contents Index checklists

Design Standards or Style Guides Examples (ISU iGuide)

http://www.iwss.ilstu.edu/iguide/

Usability Goals Usability (Bennett, 1979)

The capacity to be used by humans easily and effectively, where

Easily: to a specified level of subjective assesment

Effectively: To a specified level of human performance

Common Usability Problems Ambiguous menus and icons Unclear step sequences More steps to manage interface

that to do tasks. Inadequate feedback and

confirmation

Measures of Usability 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 Effectiveness

Level of performance Be specific here (required percentage)

Learnability Within some specified time (learning curve)

Flexibility Allowing adaptation to some specified

percentage variation in tasks Attitude

Levels of tiredness, discomfort, frustration…