The only way to define the human task is by including the properties

org.jbpm.task.assignment.enabled
org.jbpm.task.assignment.strategy

but the customer wants a way to define a different strategy to each task in the same process. 

1. To be able to implement several strategies for assigning the tasks in the same process.
2. That at design time the assignment strategy of a task can be configured

Something like:

1. Design a process with three human tasks (Task01, Task02, Task03). Design can be one task after another or tasks in parallel.
2. Task Task01 will be assigned to GroupA, it has no assignment strategy.
3. Task Task02 will have the assignment strategy "RoundRobin" and will be assigned to group GroupB.
4. Task Task03 will have the assignment strategy "PotentialOwnerBusyness" and will be assigned to group GroupC.
5. Instantiate a process
6. Verify that each task is assigned according to the indicated strategy.
7. Execute the following actions to the tasks to validate their operation: released, nomination, reassignment, forwarding

Solution

Provide an implicit AssignmentStrategy to the task so it could be used to specify explicitly which strategy to use.
The variable will be "AssignmentStrategy" in the input variable of the user task.
If AssignmentStrategy is null then it won't use any assignment strategy

property org.jbpm.task.assignment.enabled shoud be enabled