Biogas plant could sustainably solve the waste issues in the high-intensity area of small-scale swine farms. Additionally, it can provide additional revenues by selling electricity and fertilizer. Accordingly, this work was to find the optimal business models of centralization and decentralization biogas plants by considering the suitable biogas plant location and transportation in Ratchaburi province, Thailand. Geographical Information System (GIS) and economic assessment of two operation models were considered. The central feature function with simple additive weight was used to analyse the suitable biogas plant location while the suitable transportation route for collecting feedstock was analysed by the function of network analysis. The analytical results showed that the optimal location of the 0.1 MW biogas power plant was located at Mueang Ratchaburi district where the highway was connected with the location of the power plant making convenient for transportation. The shortest travel distance in one trip per day from selected small-scale swine farms was 96 km. In addition, the economic assessment of operational models between centralization and decentralization was compared by considering financial indicators including net present value (NPV), internal rate of return (IRR), benefit-cost ratio (B/C), and payback period (PB). The costs of biogas plants comprising transportation cost of feedstock, investment, operating and maintenance costs, and benefits of biogas plants were considered. The results of the economic feasibility analysis of the different operational models revealed that centralization was optimal, feasible, and profitable. The NPV, IRR, B/C, and PB were 664,430 USD, 28 %, 3.38, and 4.02 years, respectively.