jBPM user guide

工作流
要素：任务、参与者

工作流系统
工作流的管理、
工作流的调度执行、工作流引擎

任务创建时可以指定参与者也可以不指定
角色和人的对应关系

5.1. Process
definition, process instance and executions

One process instance represents one particular run of a process
definition. For example, the loan request of John Doe last Friday to
finance his new boat is represented in one process instance of the loan
process definition.

A process instance contains all the runtime state.
can be done in parallel.

5.2. ProcessEngine
5.3. Deploying a process
5.4. Deleting a deployment
5.5. Starting a new process instance
 It is a best practice to use a user defined business key.

5.6. Signalling a waiting execution

In some cases, the execution that arrives in a state will be the process instance itself.
But that is not always the case.  In case of timers or concurrency,

The preferred way to capture the right execution is by associating an event listener to the state activity

There is an alternatively (less preferrable) way to obtain the executionId
when the execution arrives in the state activity.

5.7. TaskService
The primary purpose of the TaskService is to provide access to task lists.

5.8. HistoryService
And from those events, history information on both running and completed process executions are
collected in the history tables. 
The HistoryService provides access to that information.
  
5.9. ManagementService
The management service is mostly used to manage the jobs.

5.10. Query API
Queries can be written in a unified way on all major jBPM concepts:
 Process Instances, Tasks, Deployments, Historical processes, etc.
6.2.5.3. end multiple
A process can have multiple end events.
6.2.5.4. end state
  end ---  completed
  end-cancel --- cancel
  end-error  --- error
6.2.6. task
Creates a task for a person in the task component.
6.2.6.4. task swimlanes
  Multiple tasks in a process can be associated to a single swimlane.
    A swimlane can also be considered as a process role.
  Swimlanes can be declared inside a process element

In some  cases, this might boil down to（浓缩） authorization roles in the identity component.
But bare in mind（裸记） that it is not always the same thing.

6.2.8. custom
   Invokes user code that implements custom behaviour of an activity.
Chapter 8. Scripting  
Only jUEL is configured as the scripting language. 
jUEL is an implementation of the Unified Expression Language.
To configure other scripting languages then jUEL, please refer to the developer's guide (non supported).