Long-term energy planning models and dispatch simulations are two key stages in the methodology for a cost-effective transition to a low-carbon power system. Although these stages are equally important, they are often performed independently. This decoupled approach can lead to future investment trajectories decided by long-term energy planning models with no guarantee of a reliable electricity supply. To tackle this problem, the aim of this study was to develop a general methodological framework using a multi-model approach to address adequacy requirements in the long term. An automated soft-linking model was used to successively: i. Plan the optimal power generation mix to satisfy a given level of future expected electricity demand subject to various constraints using the TIMES framework (The Integrated MAR-KAL-EFOM System). ii. Assess the adequacy of the obtained power generation mix under several climatic and operational future states using the probabilistic operational open-source model ANTARES (A New Tool for the generation Adequacy Reporting of Electric Systems). iii. Implement iterative feedback loops based on the estimated ability of different generating technologies to support peak demand (capacity credit) to ensure a total firm capacity in line with the electricity supply criterion. This methodology was applied to a case study of power generation planning in France for the period 2013-2050. The results show that using TIMES alone provides a power generation mix for 2030 that risks insufficient supply levels. On the other hand, activating iterative feedback loops over capacity-credit exogenous parameters has the potential to ensure both the economic effectiveness of the mix and the security of the electricity supply criterion set by the French public authorities.