Standard Operating Procedures (SOPs) in an ATC Unit are a specific set of procedures that specify how the unit’s controllers’ ATC responsibilities are to be co-ordinated. (EUROCONTROL EATM Glossary of Terms)
Within ATM, many types of procedure are rigidly applied, especially in regard to communication. However, with other types of procedure modification may be permitted to suit individual situations and personalities. Nevertheless, it should be remembered that standard procedures are based on long years of experience; if there is intent to modify an existing procedure, careful consideration must be given to ensure that unforeseen consequences do not result.