As per the 'World Energy Outlook 2022' projections, 660 million people worldwide (mostly from rural areas) would be without electricity access in 2030. There are three main approaches to rural electrificationcentralised grid extension, mini-grids, and solar home systems (SHS) including pico-solar. Mini-grids are considered a promising solution in rural areas with higher reliability (as compared to the central grid) and higher capacity to meet demand (as compared to the SHS). However, there have been failures of several mini-grid projects worldwide. There are various challenges faced by mini-grids -technical, social, economic, and strategic. The past efforts to assess mini-grid sustainability have used static approaches. Consideration of dynamic variations in the mini-grids over the life cycle for sustainability assessment is an emerging research area and is being explored in this paper. An attempt has been made to show how the dynamics and the interdependency of different aspects related to the mini-grids can be considered for life cycle sustainability assessment. Complex environments, local operations, many interacting variables, and feedback processes characterise mini-grids. 'System dynamics' is a systems method suitable to describe behaviours of such systems and tackle relevant problems. A system dynamics approach has been used in assessing an Indian mini-grid for a systemic understanding of its life cycle. The analysis reveals the impact of different variables on the mini-grid's life cycle. Developed stock-flow (SF) diagram is useful for analysing different scenarios (e.g. arrival of centralised grid) and policies (e.g. tariff variations). This proof-of-concept (PoC) may help to develop a comprehensive framework for the dynamic life cycle sustainability assessment (D-LCSA) of mini-grids.