The global demand for rubber is ever-increasing. As consumption levels grow, so do the environmental problems which accompany manufacturing. Environmental responsibility is now a pressing issue worldwide, and the Thai Rubber industry is no exception. As a consequence of green measures, pressure has been put upon this industry to design a supply chain which will be environmentally friendly whilst still allowing economic gain. While current research on the Thai Rubber supply chain is available, however, none of the early works deal with issues that address economic benefits and environmental maintenance as twin, or connected concerns.

The objective of this thesis therefore, is to develop a decision-support model for the Thai Rubber industry supply chain. Specifically, the model assists in managing the Thai Rubber supply chain such that it may achieve economic gain whilst remaining environmentally friendly. In order to achieve this goal, a Green Supply Chain Management (GSCM) modelling approach was adopted. Linear-programming based single objective and multi-objective optimisation was chosen for the model development and formulation. The model was formulated by incorporating information regarding the production, distribution, and transportation of rubber products in such a manner that total costs and total GHG emissions would be minimised both separately and simultaneously. The objective of minimising the total costs represents economic performance, while the objective of minimising total GHG emissions indicates environmental performance.

The results show that by using the linear programming based single objective model, the total cost of rubber production could be improved by 1.56% relative to current industrial practice. With regard to GHG emissions minimisation, the optimal GHG emissions minimisation is 1.08 tons of GHG emissions per ton of product. An important insight gained from this model is that farmer production and manufacturing process costs are incompatible with GHG emissions optimal results;​ while the results are compatible with outbound distribution transportation. However, these two objectives conflict when transport and distribution networks are restructured. In its current state, the relationship between costs and GHG emissions in the Thai Rubber supply chain, are by nature, conflicting. Consequently, a multi-objective optimisation model was developed to incorporate these two objective functions in order to capture the trade-offs between costs and GHG emissions in the supply chain network. Multi-objective optimisation along with the results of the optimisation scenario analysis concluded that a transportation restructure is more beneficial to the environment than a distribution restructure. However, from an economic perspective, restructuring distribution, along with the development of new transportation routes, appears to result in the best compromise, in that notable cost reductions may be achieved, and environmental damage is somewhat mitigated.

The contribution of this thesis were at the modelling level where GSCM modelling was captured, and at the industrial level where the Thai Rubber industry would benefit from using this model to manage the supply chain for the purpose of cost savings and GHG emissions reduction. For modelling level contribution, the single objective functions GSCM model, which was developed at the initial stage of this thesis, provided a comprehensive understanding of the basic elements of the model in relation to costs and GHG emissions. The multi-objective model provided a full set of trade-off solutions between costs and GHG emissions. From the set of alternative solutions provided, the decision maker can investigate and select the supply chain network design that most satisfies their preferences. In term of industrial level contributions, the decision-support tool can assist those in the Thai rubber industry to improve rubber production costs and decrease GHG emissions. Furthermore, supply chain network designs are able to improve policy implementation in the Thai Rubber supply chain. The establishment of rubber zoning was proposed as a way of managing the unstructured Thai Rubber supply chain. Rubber zoning can be used to support any policy related to the rubber industry. This includes:​ land use control for new plantations, rubber manufacturer zoning, number of traders in each region and transport infrastructure investment.