Orientation: Auditors have to exercise complex, multi-dimensional evidence-planning judgements. Research purpose: Drawing on social closure theory, the aim of this study is to develop a model to inform the flexible exercise of judgement regarding the types, extent and combinations of audit procedures implemented to gather sufficient appropriate audit evidence to respond to the assessed risks of material misstatement. Motivation for the study: The exercise of considerable judgements by auditors may mean that little consistency is achieved regarding the quantity and quality of the audit evidence obtained, especially in the public sectors of developing countries (which are often plagued by corruption), and where auditors and auditees have limited skills and experience. Research approach, design and method: The study employs a theory-building approach to develop a model intended to guide public sector auditors (following an audit risk approach), to exercise planning judgements for a class of transactions, account balance and/or disclosure. Main findings: The model clarifies the audit evidence decision-making sequences, interrelationships and contingent dependencies of the different audit procedures, and quantifies the compensatory inter-relationships between the types of audit procedures to be performed and the overall levels of assurance desired in response to the assessed risks of material misstatement. Practical and managerial implications: The model could aid public sector auditors to reduce uncertainty, ambiguity and judgement errors during their planning decision-making. Contribution or value-add: The model has been incorporated into the audit methodology of the Auditor-General of South Africa, and has been assessed for compliance with the International Standards on Auditing by the Independent Regulatory Board for Auditors in South Africa.