Activities involving multiple participants need to be coordinated. It requires parties schedule joint activities together. Multi-party scheduling consists of the development of schedules across organisational groups. Where uncertainty and ill-defined information are involved, human cooperation is vital in making decisions. Schedulers view a range of tasks and plans as common. However, their domain knowledge differs and they have individual goals and tasks. Hence, cooperative and individual activities must be harmonised, in a holistic framework of true collaborative state. This paper analyses the schedulers’ cooperative activities when coordinating joint tasks. It sets a foundation for studying their behaviour cooperating. A model of Cognitive Work Analysis for decision-making with multiple goals is applied and extended to include interactions between collaborators. The interactions are cooperative activities, where cooperation is viewed as a process of interference management.