Two events belong to the same activity instance if they have the same activitytemplate ID (ATID) and the same process instance ID (PIID).
如果两个事件具有相同的活动模板 ID （ATID）和相同的流程实例 ID（PIID），那么这两个事件就属于同一个活动实例。
2
Custom properties are available after they have been set for the process or activity instance, or in all task states, when they are set on the process or activitytemplate.
Composing element, composing mode and cooperative working policy of CBWG are described and concepts such as cooperative activity, activitytemplate and activity tree are introduced.