Data. How the data is useful for preparing a budget . f. income and expenditure for previous time periods g. departmental .event or project budgets h. grant funding guidelines or limitations i. performance information from previous periods 15. Explain the importance of each oflhe following budget preparation practices Practice Impedance a. management policies and procedures b. organisational budget preparation guidelines 16. Describe two techniques tor making budget estimates 1?. Explain the concept of budget deviation management 18. Give three common reasons for deviations from budgets