A maintenance time prediction method considering ergonomics through virtual reality simulation

SpringerPlus

Table 1 The MOD method classification of basic therbligs

Classification	Details	Sign
Move action
Move	Finger movement	M1
	Wrist movement	M2
	Forearm movement	M3
	Upper arm movement	M4
	Straighten the arm movement	M5
Reflex motion	Continuous repeatedly reflex action	M1/2, M1, M2
End up action
Grasping motion	Touch or contact	G0
	Grab without attention	G1
	Complicated capture	G3
Putting motion	Simple placement	P0
	Complex placement, as alignment	P2
	Placement aimed at assemble	P5
Other action
Feet motion	Cadence motion	F3
Thigh motion	Walk action	W5
Independent motion (other actions have to stop)	Visual inspection	E2
	Correction	R2
	Judgment and reaction	D3
	Press down	A4
Body movements at the same time	Spins	C4
	Stoop/curve body → Stand up	B17
	Sit down → Get up	S30
Additive factor	Gravimetric factor (Load)	L1