ABSTRACT How can a process be flexible enough for use in any incident, yet rigid enough to provide the structure required in times where stress is high, and time is short? In 2014 the IPIECA-IOGP Joint Industry Project (JIP; an outcome of the 2010 Gulf of Mexico oil spill) recommended the implementation of a structured Incident Management System (IMS) in their publication of a Good Practice Guide (GPG): Incident Management System for the Oil and Gas Industry. Now, half a decade on from this publication, many oil companies have, or are in the process of implementing some form of IMS across their global operations. The GPG describes IMS as a “set of proven organizational and management principles.” It also states that it is based on ICS as it “is a version of IMS that is widely used by Industry”. As multiple IMS's exist globally, this paper explores whether the blanket adoption of a single existing system can be used when so many considerations, are required. Through observing and assisting their members in introducing (and maintaining) an IMS across various business units, Oil Spill Response Limited (OSRL) has seen how systems can be tailored that are flexible enough to meet the specific needs of the company concerned. Examples include introducing initial assessment procedures and customisation of documentation. Potential limitations of ICS possible evolutions of IMS are discussed. Incorporation of the organisational and management principles described by the JIP provides guidance when modifying/tailoring a system that can be used by businesses facing different scenarios in different environments and with differing levels of resources. The change in terminology from the Incident Command System to the Incident Management System allows for customisation of a proven system and increased flexibility whilst being based on tried and trusted foundations.