Human Aspects of System Design Introduction

Human Aspects of System Design

• Introduction

• Designing the human element into a system is paramount to its success
• One error incorporated by the human into the system could bring a major catastrophe
• Some Examples:

System Design Process

• Molecularization

• System Definition

• Limitation & Constraints

• Transformation

• Iteration

• Competition

• Relevance

Molecularization

Characteristics of a System Design Process

• Requirements of the system define options

• Limitations and processes that are unsure

Characteristics of a System Design Process

• Transformation

• Time and Cost Constraints

Characteristics of a System Design Process

• Iterative Cycle

Characteristics of a System Design Process

• Competition between groups within the design team

• Relevance to the design

Six Major Stages in the Design Process

Six Major Stages in the Design Process

• STAGE 1 : System Requirements

• Determine the objectives and principles of the process

• Objective

• - purposes of the system

• - general terms

• - details what system is to do to meet objectives

• - defines constraints

• System Performance Specifications

Two HF activities appropriate at Stage 1

• Two HF activities appropriate at Stage 1

• (1) Identify all users of the machine

• (2) Identify the activity-related needs of users which the

• system will be responsible for

STAGE 2 : Definition of the system

• STAGE 2 : Definition of the system

• Define system functions to meet performance criteria

STAGE 3 : Basic Design

• STAGE 3 : Basic Design

• Allocation of functions to human, computer, and software

• Some Guidelines for Designers

Guidelines to Allocate Functions

• Guidelines to Allocate Functions

• (1) Mandatory Allocation

(2) Balance of Value

• (2) Balance of Value

(3) Utilitarian and cost-based allocation

• (3) Utilitarian and cost-based allocation

• (4) Affective and cognitive support allocations

STAGE 4 : Interface Design

• STAGE 4 : Interface Design

STAGE 5 : Facilitator Design

• STAGE 5 : Facilitator Design

STAGE 6 : Testing and Evaluation

• STAGE 6 : Testing and Evaluation