In this study we report the result of an empirical study investigating simulation modelling practices and processes of expert modellers in business and industry. The results suggest that most of the participants do not have a clearly defined or a formal process for developing their models, rather a set of key steps or stages depending on certain contextual factors and personal style. A number of contextual factors such as the problem domain, the scope of the problem, the size and complexity of the model, may affect the way a modeller goes about developing his/her simulation models. Generally a three phased approach is identifiable which can be named as problem definition, model development, and model usage. Model documentation largely depends on model life, client requirement, and type of model being developed. Maintenance and reuse of model is generally not practiced, given most of the models developed are of short to medium term use; however, experience and knowledge is something that is reused.