Environmental impact assessment of manufacturing processes using a combinatorial mathematics based decision making method

Figures & data

Table 1. Values of environmental impact assessment factor.

Qualitative measures of environmental impact assessment factor	Assigned values
Exceptionally low	0.045
Extremely low	0.135
Very low	0.255
Low	0.335
Below average	0.410
Average	0.500
Above average	0.590
High	0.665
Very high	0.745
Extremely high	0.865
Exceptionally high	0.955

Figure 1 Linguistic terms to fuzzy numbers conversion(11‐point scale).

Table 2. Assessment of the toy train for 12 different scenarios (Choi et al. 1997).

Scenario	Description of assessment
1	The original toy train model
2	Based on ‘1’, but the production method of the wheel was changed from machining to die casting
3	Based on ‘1’, but the production method of the wheel was changed from machining to injection moulding
4	Based on ‘1’, all bushes and screws were removed and three shafts were added
5	Based on ‘4’, but the production method of the wheel was changed from machining to die casting
6	Based on ‘4’, but the production method of the wheel was changed from machining to injection moulding
7	Based on ‘1’, the concept of recycling was introduced. This meant if any material can be reused or recycled, no solid waste was involved
8	Based on ‘7’, but the production method of the wheel was changed from machining to die casting
9	Based on 7, but the production method of the wheel was changed from machining to injection moulding
10	Based on ‘4’, the concept of recycling was introduced. This meant if any material can be reused or recycled, no solid waste was involved.
11	Based on ‘10’, but the production method of the wheel was changed from machining to die casting
12	Based on ‘10’, but the production method of the wheel was changed from machining to injection moulding

Table 3. Assessment results for the toy train for 12 different scenarios (Choi et al. 1997).

Scenario	Solid waste (mm^3)	Energy consumption (kWh)	Waste water (m^3)
1	476,743	1.252	0.879
2	458,449	0.892	0.524
3	473,311	0.892	0.524
4	457,146	0.815	0.526
5	438,852	0.455	0.172
6	453,714	0.455	0.172
7	51,023	1.252	0.879
8	30,593	0.892	0.525
9	30,617	0.892	0.525
10	31,426	0.815	0.526
11	10,996	0.455	0.172
12	11,020	0.455	0.172

Table 4. Normalised assessment results for the toy train for 12 different scenarios.

Scenario	Solid waste (mm^3)	Energy consumption (kWh)	Waste water (m^3)
1	0.02306	0.3634	0.1957
2	0.0240	0.51	0.3282
3	0.0232	0.51	0.3282
4	0.02405	0.5583	0.3270
5	0.02505	1	1
6	0.02423	1	1
7	0.2155	0.3634	0.1957
8	0.3594	0.51	0.3276
9	0.3591	0.51	0.3276
10	0.3499	0.5583	0.3270
11	1	1	1
12	0.9978	1	1

Table

Scenario 11:	6.3552
Scenario 12:	6.3508
Scenario 5:	4.4054
Scenario 6:	4.4038
Scenario 10:	3.6544
Scenario 9:	3.6121
Scenario 8:	3.6116
Scenario 4:	3.2691
Scenario 2:	3.2216
Scenario 3:	3.2207
Scenario 7:	3.1453
Scenario 1:	2.9392

Choi , A. C. K. , Kaebernick , H. and Lai , W. H. 1997 . Manufacturing processes modelling for environmental impact assessment. . Journal of Materials Processing Technology , 70 : 231 – 238 .

 Google Scholar