Purpose: Although software systems used to automate business processes have been becoming rather advanced, the existing practice of developing and modifying graphical process models in those software systems is still primitive: Users have to manually add, change, or delete each node and arc piece by piece. Because such manual operations are typically tedious, time-consuming, and prone to errors, it is desirable to develop an alternative approach.Design/methodology/approach: In this paper, we develop a novel, human-understandable process manipulation language (PML) for specifying operations (e.g., insertion, deletion, merging, and split) on process models. We also develop a prototype system to demonstrate PML. Findings: Manipulation operations on process models can be standardized and, thus, can be facilitated and automated through using a structured language like PML.Originality/value: PML can improve manipulation operations on process models over the existing manual approach in two aspects: First, using PML, users only need to specify what operations are to be performed on process models, and then a computer carries out specified operations as well as performs other routine operations (e.g., generating nodes and arcs). This feature minimizes user effort to deal with low-level details on nodes and arcs. Second, using PML, users can systematically specify operations on process models, thus reducing arbitrary operations and problems in process models