This book chapter intends to equip the readers with the basic understanding of what crop models are, answer the common questions which the crop-modelling community usually receives from the other research disciplines, and briefly describe the frequent model misuses which many times hamper broader usage of models in agriculture. We will briefly discuss the diversity of crop models and usage of the appropriate modelling tool to address the questions relevant in crop improvement programs (focus on sorghum/cereals models; APSIM). Furthermore, we will use several examples focusing on sorghum crop of how modelling approaches are currently being deployed to accelerate agricultural/cropping systems production and resilience improvement. Here, we will depict few examples of sorghum model development necessary to reflect agricultural systems in developing countries (e.g., challenges specific to model sorghum crop in Africa). We will point out to emerging directions of model development needed to address some of the global developmental goals and challenges.