Fig. 1

Fig. 2

Fig. 3

Pairwise comparison scale (Saaty 1980)_
| Value of aij | Definition |
|---|---|
| 1 | i and j are equally important |
| 3 | i is slightly more important than j |
| 5 | i is more important than j |
| 7 | i is strongly more important than j |
| 9 | i is absolutely more important than j |
| 2, 4, 6, 8 | Intermediate values between the two adjacent judgements |
Collected data for structural system alternatives_
| Alternatives | C1 (Euro) | C2 (day) | C3 (year) | C4 (score) | C5 (score) | C6 (score) | C7 (score) | C8 (score) | Cα |
|---|---|---|---|---|---|---|---|---|---|
| On-site RC structural system | 66,631.47 | 120 | 50 | 3.54 | 1.82 | 3.90 | 3.39 | 2.98 | 0.826 |
| PRC structural system | 60,403.60 | 100 | 60 | 3.31 | 2.71 | 3.41 | 3.35 | 3.49 | |
| Steel structural system | 71,249.16 | 80 | 80 | 3.85 | 4.27 | 2.72 | 3.74 | 3.96 |
The pairwise comparison of alternatives with respect to the suitability for installation_
| Suitability for installation | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 2 | 1/3 |
| PRC structural system | 1 | 1/2 | |
| Steel structural system | 1 |
The pairwise comparison of alternatives with respect to the natural lighting needs_
| Natural lighting needs | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 1/3 | 1/5 |
| PRC structural system | 1 | 1/2 | |
| Steel structural system | 1 |
The pairwise comparison of alternatives with respect to the project duration_
| Project duration | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 1/3 | 1/5 |
| PRC structural system | 1 | 1/3 | |
| Steel structural system | 1 |
The results of the TOPSIS method_
| Alternatives | Si+ | Si− | Ci* | Normalised Ci* | Rankings |
|---|---|---|---|---|---|
| On-site RC structural system | 0.068417 | 0.043787 | 0.390 | 0.274 | 3rd |
| PRC structural system | 0.048043 | 0.035565 | 0.425 | 0.299 | 2nd |
| Steel structural system | 0.043976 | 0.068460 | 0.609 | 0.427 | 1st |
The pairwise comparison of the evaluation criteria_
| Criteria | C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8 |
|---|---|---|---|---|---|---|---|---|
| C1 | 1 | 2 | 2 | 3 | 2 | 2 | 2 | 5 |
| C2 | 1 | 1/2 | 2 | 4 | 1/2 | 2 | 6 | |
| C3 | 1 | 3 | 4 | 3 | 2 | 7 | ||
| C4 | 1 | 2 | 1/5 | 1/3 | 2 | |||
| C5 | 1 | 1/6 | 1/4 | 2 | ||||
| C6 | 1 | 2 | 8 | |||||
| C7 | 1 | 4 | ||||||
| C8 | 1 |
The pairwise comparison of alternatives with respect to the project cost_
| Project cost | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 1/3 | 2 |
| PRC structural system | 1 | 4 | |
| Steel structural system | 1 |
The decision matrix of the TOPSIS method_
| Alternatives | C1 (Euro) | C2 (day) | C3 (year) | C4 (score) | C5 (score) | C6 (score) | C7 (score) | C8 (score) |
|---|---|---|---|---|---|---|---|---|
| Wi (weights) | 0.218 | 0.133 | 0.212 | 0.058 | 0.047 | 0.191 | 0.114 | 0.027 |
| On-site RC structural system | 66,631.47 | 120 | 50 | 3.54 | 1.82 | 3.90 | 3.39 | 2.98 |
| PRC structural system | 60,403.60 | 100 | 60 | 3.31 | 2.71 | 3.41 | 3.35 | 3.49 |
| Steel structural system | 71,249.16 | 80 | 80 | 3.85 | 4.27 | 2.72 | 3.74 | 3.96 |
Random CI (Saaty and Ozdemir 2003)_
| n | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RI | 0.00 | 0.00 | 0.52 | 0.89 | 1.11 | 1.25 | 1.35 | 1.40 | 1.45 | 1.49 | 1.52 | 1.54 |
The pairwise comparison of alternatives with respect to the recycling opportunities_
| Recycling opportunities | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 1/2 | 1/5 |
| PRC structural system | 1 | 1/3 | |
| Steel structural system | 1 |
The pairwise comparison of alternatives with respect to the resistance to environmental effects_
| Resistance to environmental effects | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 2 | 3 |
| PRC structural system | 1 | 2 | |
| Steel structural system | 1 |
Results of the AHP method_
| Alternatives | Results (%) | Rankings |
|---|---|---|
| On-site RC structural system | 25.0 | 3rd |
| PRC structural system | 32.9 | 2nd |
| Steel structural system | 42.1 | 1st |
Weights of the evaluation criteria_
| No. | Criteria | Weights |
|---|---|---|
| 1 | Project cost | 0.218 |
| 2 | Project duration | 0.133 |
| 3 | Project lifetime | 0.212 |
| 4 | Labour and equipment requirement | 0.058 |
| 5 | Recycling opportunities | 0.047 |
| 6 | Resistance to environmental effects | 0.191 |
| 7 | Suitability for installation | 0.114 |
| 8 | Natural lighting needs | 0.027 |
The pairwise comparison of alternatives with respect to the project lifetime_
| Project lifetime | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 1/2 | 1/5 |
| PRC structural system | 1 | 1/3 | |
| Steel structural system | 1 |
The pairwise comparison of alternatives with respect to the labour and equipment requirement_
| Labour and equipment requirement | On-site RC structural system | PRC structural system | Steel structural system |
|---|---|---|---|
| On-site RC structural system | 1 | 2 | 1/3 |
| PRC structural system | 1 | 1/2 | |
| Steel structural system | 1 |