Table 5. Cost factors and assumptions used for operation cost analysis.

Cost factor		Machine
			Excavator		Head
Price (won)	(P)		110,000,000		110,000,000
Endurance perioda (years)	(N)		7		8
Economic life (hour)	(H)		9,744		11,136
Annual operation timeb (hour)	(J)		1,392		1,392
Fuel consumption (liter/hour)	(c)	12.8	9.0	16.8	-
Coefficient of repair and maintenance	(r)		0.8		0.8
Coefficient of lube oil	(l)		0.4		0.4
Interest rate (%/year)	(i)1		10		10
Depreciation (won/hour)	P/H or P(N·H)		11,289		9,878
Interest expense (won/hour)	0.5ㆍPㆍiㆍ0.01/J		3,951		3,951
Costs of repair and maintenance (won/hour)	P/Hㆍr		9,031		7,902
Fuel costc (won/hour)	cㆍlㆍ(1+0.1)	28,063	19,732	36,832	-
Other cost (won/hour, Insurance, storage fee etc.)	-		158		138
Sub total	-	52,492	44,161	61,262	21,870
Labor costd (won/hour, 50% Inclusion incidental expense)	-		43,064		-
Total machine cost (won/hour, Inclusion labor cost)	-	95,556	87,225	104,326	21,870
		117,426e		109,095f	126,196g

174day×8hour=1,392hours (Korea Forest Service, 2012)
Endurance period (Miyata, 1980; Woo et al., 1997; Brinker et al., 2002)
Diesel : 1,566won/liters in 2022, South Korea (Korea National Oil Corporation, 2022)
Standard of labor cost: machine operator (229,676won/day) (Construction Association of Korea, 2022)
Machine cost of felling and processing operation,
Machine cost of felling operation,
machine cost of processing operation