Table 9.

Variable Importance of the Proposed Decision Tree Model.

Variables/Attributes	Importance Score
Source of injury: Parts and materials	49
Source of injury: Tools, instruments, and equipment	13
Source of injury: Structures and surfaces	11
Human factor: Malfunction in lockout/tagout procedure	9
Environmental factor: Other	6
Environmental factor: Overhead moving- or falling-object action	4
Cause of injury: Interior plumbing, ducting, and electrical work	4
Environmental factor: Work surface or facility layout condition	2
Project type: New project or new addition	1
Cause of injury: Other	1