Process Based Lca Essay

2.1 LCA model
Life cycle assessment (LCA) is an effective tool for quantifying the environmental burden of products, processes or services during their life cycle from cradle to grave (ISO, 2006). Various LCA studies have been conducted in the energy and environment fields. LCA approaches can be divided into three: process-based LCA, IO LCA, and hybrid LCA.
The process-based LCA requires information on energy, material, and resource inputs and environmental outputs for each stage in the product life cycle. The process-based approach was defined in the ISO 14040 framework, the general steps include goal and scope definition, inventory analysis, impact assessment, and interpretation (ISO, 2006). The advantages of process-based LCA are the detailed

A hybrid LCA is integrated process-based and IO LCA, to balance between time and costs efficiency. Based on the hybrid LCA models, the upstream impacts of goods could be included with economy-wide scope, and impacts in the production, usage and end-of-life phases could be specifically analyzed (Bilec et al., 2010).
The social impacts are effects on the sustainable operation of society such as employment, salaries, and occupational safety. A social LCA is a social impact (and potential impact) assessment technique that aims to evaluate the social and socio-economic aspects of products and their potential positive and negative impacts during their life cycle including: extraction and processing of raw materials, manufacturing, distribution, use, re-use, maintenance, recycling, and final disposal (UNEP, 2009). Comparison between the environmental LCA and social LCA, the social LCA in research scope and framework has not been fully formed and needs further development.
2.2 Social inventory database development based on IO model
The IO model is widely applied to conduct national economic analyses and used to assess macro-economic impacts of production change. This study uses the 2005 IO table of Thailand which consists of 180x180 sectors in the analyses by aggregating it into a new format (96x96

This study developed the input coefficient matrix based on the 2005 economic IO table of Thailand with aggregated data into 96x96 economic sectors.
2.2.2 Matrix of social footprint coefficient
The modified IO model adds a row for social aspects to show the social issues involved in production processes, thus quantifying the social footprint for the final demand in different sectors. The social footprint matrix (S) is the extension of the direct input coefficient matrix for social issues. Where S is a k x j matrix, skj is social issue k (e.g. employment, accident cases) per monetary output of sector j. The matrix S is defined as:
S = skj = Skj / Xj (k = 1,…, m; j = 1, … , n) (2)

This study analyzes six different social impacts, the dimensions of the social aspects matrix are S (6 x 96). Elements in the social aspects matrix reflect the impacts per sectoral output, e.g., 100 working-hours per one thousand Thai Baht for the paddy rice sector.
2.2.3. Final demand