The Village Poultry Simulation Model (VIPOSIM) is a dynamic deterministic model developed to simulate the dynamics of village poultry flocks. The model was developed at Wageningen University, in the Netherlands, and validated with data from Tigray, Ethiopia. VIPOSIM takes into account the complex and dynamic aspects of a village poultry production system by incorporating five processes related to chicken production and management (flock offtake, egg production, egg loss, egg offtake and reproduction). The model performs calculations in time steps representing reproduction cycles. Each step has a length of three months (seasonally) and the maximum number of steps in the model is twelve, which corresponds to a period of three years. The economic parameters such as prices of birds and eggs and costs of production are also input variables in the model. VIPOSIM categorises total costs from the input costs of labour and costs of intervention. The model also incorporates the standard deviations of each input parameter.