A flowchart is primarily used to evaluate the design of controls by visually representing the sequence of operations, decision points, and control activities within a process. This helps the internal auditor identify weaknesses, redundancies, and gaps in internal controls.
* Preparing for testing the effectiveness of controls (A) comes later in the audit process, after evaluating the design.
* Planning for evaluating potential losses (B) focuses on risk assessment rather than control design.
* Preparing a sampling plan (C) is a different step in the audit process, where the auditor determines the scope and sample size.
Reference:IIA's International Professional Practices Framework (IPPF) - Implementation Guide 2200:
Engagement Planning.