Process auditing represents the highest level of control within an implemented business process and its instances. An audit may be done either formally in accordance with the methodology of the type of business process management (BPM) being used, or rather informally in the case of agile process management. What is important, however, is that through the auditing a complete and deep review of a process takes place from the point of view of its completeness, being up-to-date, effectiveness, etc. While a common process review could be described as a kind of necessary regular maintenance, a process audit goes much further and represents a kind of general overhaul — disassembling the whole down to its components, checking them and possibly replacing the outdated ones if necessary. An audit is done either by the process owner, chief process officer or an experienced process consultant.