Auditor is required to plan the audit by developing an audit strategy to guide the plan itself. Audit plan is necessary for number of reasons of which the foremost is to achieve audit efficiency and effectiveness. Audit plan involves planning risk assessment procedures, further audit procedures and other audit procedures to obtain sufficient appropriate audit evidence. During the audit if auditor concludes that initial plan requires alteration then auditor shall consider revising audit strategy as well if needed. Change in audit plan involves change in the scope timing or extent of planned audit procedures. Auditor shall document the audit plan and any changes thereto.