1

Reason’s Model/Human Factors Analysis Classification System

AVIA 4000, Special Projects: Human Factors in Aviation

Raymond E. Cain, Jr., Ph.D., Instructor

Learning Objectives

• After this unit of instruction, the student will be able to demonstrate the following:

– An operable understanding of Reason’s and the HFACS models

– An operable understanding of the relationships among human error, human factors, and Reason’s and the HFACS models

3

Reason’s Model

• Introduced by James Reason

• Two ways to look at the Human Error Problem

– The person approach—focus on the errors of individuals; blame them for forgetfulness, inattention, or moral weakness

– The systems approach—concentrate on conditions under which individuals work and build defenses to avert errors or mitigate their effects

4

Systems Approach (Reason’s)

• Basic premise: humans are fallible and errors are to be expected, even in the best organizations

• Errors are seen as consequences not causes

5

Reason’s Premise #1

6

Reason’s Premise #2

7

Reason’s Premise #3

8

Reason’s Premise #4

9

Reason’s Premise #5

10

Reason’s Model

11

HFACS

• Human Factors Analysis Classification System

12

Unsafe

Acts

Adapted from Reason (1990)

Failed or

Absent Defenses

Reason’s “Swiss–Cheese” Model of Human Error (HFACS) #1

13

Failed or

Absent Defenses

Preconditions

for

Unsafe Acts

Unsafe

Acts

Adapted from Reason (1990)

Reason’s “Swiss–Cheese” Model of Human Error (HFACS) #2

14

Failed or

Absent Defenses

Unsafe

Supervision

Preconditions

for

Unsafe Acts

Unsafe

Acts

Adapted from Reason (1990)

Reason’s “Swiss–Cheese” Model of Human Error (HFACS) #3

15

Failed or

Absent Defenses

Organizational

Factors Inputs

Unsafe

Supervision

Preconditions

for

Unsafe Acts

Unsafe

Acts

Adapted from Reason (1990)

Accident & Injury

Reason’s “Swiss–Cheese” Model of

Human Error (HFACS) #4)

16