The purpose of the cost plan is to allocate the budget to the main elements of the project to provide a basis for cost control. The terms budget and cost plan are often regarded as synonymous. However, the difference is that the budget is the limit of expenditure defined for the project, whereas the cost plan is the definition of what the money will be spent on and when. The cost plan should, therefore, include the best possible estimate of the cash flow for the project and should also set targets for future running costs. The cost plan should cover all stages of the project and will be the essential reference against which the project costs are managed.