Incorporating Variability in Lean Manufacturing: A Fuzzy Value Stream Mapping Approach

Table 6

Cycle time and WIP for future-state value stream map (1).

	Estimated value			TFN	NFN
	a	b	c
Raw material inventory (hours)	0	4	8	(−0.44, 4.00, 8.44)	(4.00, 1.33)
Cutting (s)	16	20	26	(15.56, 20.00, 26.67)	(19.84, 1.89)
Buffer 1 (hours)	2	3	4	(1.88, 3.00, 4.11)	(3.00, 0.33)
Prefitting (s)	25	30	35	(24.44, 30.00, 35.56)	(30.05, 1.60)
Buffer 2 (hours)	2	3	4	(1.88, 3.00, 4.11)	(3.00, 0.33)
Computer stitching (s)	300	320	340	(297.78, 320.00, 342.22)	(320.60, 6.25)
Manual stitching (s)	270	300	340	(266.67, 300.00, 344.44)	(298.06, 11.24)
Assembly (s)	480	510	560	(476.67, 510.00, 565.56)	(510.58, 12.61)
Buffer 5 (hours)	0	4	8	(-0.44, 4.00, 8.44)	(4.00, 1.33)

Note: the NTNs of cutting, prefitting, computer stitching, manual stitching, and assembly do not change with the current state.