The alarm management lifecycle model of ISA (International Society of Automation) establishes recommended processes for a plant alarm system. To realize the lifecycle, a BPM (business process model) for appropriate management of change in the plant alarm system is required. The following two-step approach will be effective to manage change in the plant alarm system. The first step is to construct a BPM in accordance with the lifecycle based on the BPM of plant lifecycle engineering. The second step is to develop a workflow for management of change in the plant alarm system. The BPM and the business flow should not only list activities of the BPM but also specify the information to be shared and exchanged between activities, the tools and methods to be used, and the requirements of additional tools and methods for design or performance monitoring of the plant alarm system. This paper introduces the proposed tools and methods for design and performance monitoring of a plant alarm system.