Use Cases for Case Management
Case Management is useful as a notation for describing high-level business scenarios that are generic and flexible. More structured aspects are best defined using business processes and, if desired, used from within a case model.
There is some overlap in the use cases of Business Process Management and Case Management. While business processes are clearly suited for situations where there are clear responsibilities and flows, cases are more directed towards dynamic situations with a high degree of freedom. It is possible to use business processes to model dynamic situations as well, for example, by using sophisticated gateways and decision tables, however this can quickly get complex to understand and manage.
With Case Management, tasks are executed in parallel by default, within an overall structure.
One common example where Case Management excels is repeatable tasks. There is no simple way to model this in business processes as the flow keeps on progressing. With cases, a manually startable and repeatable task can simply solve this. Such a task can then, on completion, trigger a new process, another task or whatever may be appropriate. All of this can happen independently of other parts of the case, which just keep on running.
Another frequent use of Case Management is to describe the life-cycle of something, such as the status of a customer, an employee, a product or a project. Taking a project as an example, a major project may go through several phases where there are criteria for going from one phase to another. Case Management has the concept of Stages that provides a way to describe the conditions or events that say when a case can switch to another stage. This might be the criteria for a project to go from inception to planning; from cancellation to winding down; or from implementation to hand-over. It might still be Business Processes that implement the actual life-cycle changes.
In summary, a Case model should be used if the complexity cannot fully and easily be described by a Business Process model, or when a high-level overview is desired.