The author comfortably explains the concepts of systems auditing to enable the reader to put them into practice. With the integration of information technology into business systems, traditional auditing procedures and concepts need alteration. This book describes: technology, concepts-operating systems, database management systems, electronic payments systems, financial accounting systems, the standard control in different computerised environments, the procedures and methodology that auditors need to adopt, the need to build controls at the stage of systems development plus other security aspects. Through a step-by-step approach, the book familiarises auditors with the information systems. It provides guidelines for developing appropriate audit systems for the computerised environment systems specific to the needs of companies by providing generalised templates and modules.