This paper addresses deficiencies in traditional service desk models. These shortfalls affect end users, by taking a lengthy time to complete a request, support tools that cannot be upgraded quickly and change and configuration management not being easily integrated. Current diagrammatic representations, such as UML and ER, seem to contribute to these problems because they lack an integrated representation of the service desk system. This paper applies a recently developed thinging machine (TM) to create an integrated diagrammatic language to specify service desk operations. Without loss of generality, the focus is on the security aspects of service desk tasks. To show the proposed methodology's viability, we use a TM in an actual case study that is currently being implemented.