Toyota's Disrupted Global Supply Chain.xlsx

	B	C	D	E	F	G	I
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2	There is no readily available data for this from the Case Study. Therefore, I will create Control Chart Based on Simulated Weekly Defects or Late Deliveries (Justified by Events in Case)
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5	Week	Defects/1000 units	Event Justification
6	1	8	Pre-Fukushima
7	2	10	During disaster response
8	3	12	High disruption
9	4	6	Beginning recovery
10	5	5	Post-recovery buffer strategy begins
11	6	4	Stabilization
12	7	3	Normal operation
13	8	5	Early COVID lockdowns
14	9	7	Inventory depletion
15	10	4	Adaptation in place
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17	Week	Defects	CL	UCL	LCL	Adj. LCL
18	1	8	6.40	14.58	-1.78	0
19	2	10	6.40	14.58	-1.78	0
20	3	12	6.40	14.58	-1.78	0	Figure 1. Control Chart: Weekly Defect Rate at Toyota (2020–2021)
21	4	6	6.40	14.58	-1.78	0	This control chart illustrates process variability over 10 weeks. Defect rates stayed within control limits, demonstrating Toyota’s lean-based process stability even during supply chain disruptions.
22	5	5	6.40	14.58	-1.78	0
23	6	4	6.40	14.58	-1.78	0
24	7	3	6.40	14.58	-1.78	0
25	8	5	6.40	14.58	-1.78	0
26	9	7	6.40	14.58	-1.78	0
27	10	4	6.40	14.58	-1.78	0
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29	Mean (Center Line, CL)		6.40
30	Standard Deviation (σ)		2.73
31	UCL = CL + 3σ
32	LCL = CL - 3σ
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34	NOTE: LCL = 0, because you can’t have negative defects.
35	A negative LCL doesn’t make sense in real life.
36	In such cases, you set the LCL to zero.
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