Production budget planning in the building products industry is the process of committing and allocating resources to manufacture building products for 12 months ahead in order to satisfy certain criteria set by top management. It is a highly complicated and time consuming process and demands experienced production managers to handle it.This paper discusses the development of an intelligent budget planning model in the building products industry as a possible alternative to traditional operation research methods. The intelligent model is a computer-based factory simulator which automates the process of budget planning using factory attributes and intelligent production rules. An industrial case study has been conducted to validate the model and the knowledge rules. The paper has concluded that the intelligent model is a practical and considerable managerial tool for exploring and testing managerial options open to production managers.