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

Table 3

Descriptive statistics of cycle time and WIP.

	Range	Mean ± Std. deviation (i.e., μ ± σ)	K-S test
Raw material inventory (days)	(1.2, 2.7)	2.01 ± 0.31	0.061
Cutting (s)	(16, 24)	19.84 ± 1.89	0.064
Buffer 1 (days)	(0.3, 1.4)	0.80 ± 0.23	0.252
Prefitting (s)	(27, 34)	30.05 ± 1.60	0.090
Buffer 2 (days)	(1.1, 2.0)	1.49 ± 0.15	0.063
Computer stitching (s)	(303, 334)	320.60 ± 6.25	0.721
Buffer 3 (days)	(0, 0.8)	0.43 ± 0.17	0.055
Manual stitching (s)	(271, 327)	298.06 ± 11.24	0.977
Buffer 4 (days)	(0.5, 4.4)	1.91 ± 0.84	0.590
Assembly (s)	(485, 547)	510.58 ± 12.61	0.773
Buffer 5 (days)	(0.5, 4.5)	2.18 ± 0.83	0.705