BPM+ Virtual Coffee
5 min Intro to CMMN

Presented by

Denis Gagne, CEO & CTO at Trisotech

Good day and welcome to our BPM+ virtual coffee. I am Denis Gagne CEO and CTO of Trisotech, and this is a five-minute introduction to CMMN.

Some of the motivations or characteristics behind Case Management, as opposed to process management, was that we wanted to deal with business processes where the sequence of activities is not well defined. Contexts in which activities may happen in all kinds of different orders and we must deal with these evolving circumstances. We also wanted to make sure that the evolution of the Case depended on decisions made by the Knowledge Worker. The Knowledge Worker is front and center to the notion of Case Management. It is all about managing a particular context, which is the Case. To support the performance of the Knowledge Worker required that we had a great deal of flexibility due to the dynamic nature of the work. You can think of it as your input box being your Case File, a manifold where different data comes into it, and you must react to this new information and progress with the work needed by the Case. This requires a lot of adaptability to the information context where this context of information is really the Case File. We also wanted to leave to the Knowledge Worker complete control over what to do next, for him to figure out what’s the next best action. But we also wanted to provide some scaffolding to the Knowledge Worker by also providing ideas of what could be done next. These ideas of what co be done next is where the Case Plan Model comes into play.

CMMN stands for the Case Management Model of Notation, and it is an open standard produced by OMG. The spec is available at the URL here. I invite you to go and consult this specification document.

Fundamentally CMMN is about managing a context to achieve a desired outcome where the context is a Case File. A Case in CMMN consists of a Case File and a Case Plan Model. The Case Plan Model is there to help the Knowledge Worker to figure out what possible next action would be ideal in the current context, but the activities to be carried out are really decided by the Knowledge Worker. This provides a lot of flexibility where everything is decided at runtime rather than pre-defined at design time as in the case of BPMN.

CMMN is as easy as one-two-three because CMMN uses an Event-Condition-Action (ECA) semantic. This means basically that when a particular Event happens, if a condition is met, then a possible an action is available. CMMN offers all the variations of ECA. We can have Event-Condition-action or just Condition-Action or just Action. You therefore have the full flexibility of defining the needed activities.

Now looking at the CMMN notation, the folder shape depicts your context. This gives you the information context of the Case File in which you are working. We then have different symbols to capture the notions of Event, Condition and Actions. Events can be actual Event Listeners, like for example Timer Events or User Events but it can also be Case File Events. For example, a new Case File Item being provided into the Case File, or a particular information item is updated, or a document is done or updated. We use these events as triggers, and we verify whether a particular condition is met. An Entry Criterion will be a condition for entering into this element and an Exit Criterion will be the Criterion for terminating the work. We then have our actions. In this ECA depicted here we have a Timer Event trigger, so when this Event happens, if the Condition is met then I can do this Task. We also have the notion of Discretionary Tasks. The Planning Table is a way to turn on and off, and controlling, which Discretionary Tasks are available. A Planning Table at the top of the folder is managing basically the floating Discretionary Tasks within the Case context and a Planning Table on a Task is managing the Discretionary Tasks that are attached to this particular Task. We then have that when the Event happens, if the Condition is met, while I am in this Task, there are other Discretionary Tasks that I can take on. Then we have the notion of Stages, where you can structure your Plan Items and mostly helping you to create some kind of the life cycle for accomplishing the desired outcome of the Case. We also have the notion of Milestones and different triggers.

So, this is a very quick and broad review of CMMN. There is book on CMMN that I highly recommend you read. It is the CMMN Method and Style from Bruce Silver. You can go and read that book. It will give you an intro to CMMN and provide you with some Style and Method on how to do a good CMMN models.

That was our five-minute introduction to CMMN.

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