Group	Factors
Labor	Lack of labor skills
	Increase of laborer age
	Labor absenteeism
	Lack of training
	Labor personal problem
Management	Poor site management
	Poor communication
	Misunderstanding between labor and supervisor
	Lack of periodic meeting with labors
Management	Quality inspection delay
	Weather changes
	Project location
Environmental	Working with confined place
Environmental	Large project size
Material	Material shortage
	Unsuitable material storage location
	Low quality raw materials
Equipment	Old and inefficient equipment
Equipment	Tools and equipment shortages