Social aspects play pivotal role in sustainable development. However, in the field of manufacturing, where narrow attention has been paid to identify the socio-environmental impacts over the total life cycle of the manufactured products. Further, there is a necessity of analyzing social life cycle, especially in labour intensive industries. Moreover, as there are no well-defined approaches similar to Environmental Life Cycle Analysis (LCA) this methodology was developed by limiting to gate to gate phase of a manufacturing plant based on the guidelines specified by the UNEP guidelines for Social-LCA. The model expanded to five major stakeholders: workers, consumers, local community, society and value chain actors. Sub-functions related to manufacturing plants were identified as plant design, operations and administration. The model was validated through a case-study carried out in a medium scale apparel manufacturing plant with different stratum of diverse employee categories. Both qualitative and quantitative data were collected using interviewer administered questionnaire and observational guides. Conclusions were made using AHP technique by formulating as a multi criteria decision making problem. The case study revealed that the plant has achieved the satisfactory level of overall social performances. However, there are several areas to be improved namely minimum working conditions, health, safety and hygiene and plant facility systems design etc. In controversial to the above results, the most of the facilities provided in correspondence to the social aspects were mandatory requirements governed by the factory ordinance of Sri Lanka. In order to enhance the social wellbeing of different social ecologies: micro, meso and macro are necessarily considered, specifically when promoting ‘Garment without Guilt’ within medium scale apparel industries.