On Twitter someone posted to me: "Have you ever seen a short overview of BPMN that makes sense to people who have never heard of it?" Hmmm... Probably not. So here is my attempt.
Business Process Modeling Notation, or BPMN, is a process diagramming language. It describes, in a picture, the steps in a business process from start to end, an essential starting point whether you are simply documenting the process, analyzing it for possible improvement, or defining business requirements for an IT solution to a process problem. Dozens of process diagramming languages have existed since the 1980s at least, so what's so special about BPMN?
First, BPMN is an open industry standard, under the auspices of the Object Management Group. It is not owned by a particular tool or consulting company. A wide variety of tools support it, and the meaning of the business process diagram is independent of the tool used to create it. With BPMN you don't need to standardize on a single tool for everyone in the organization, since they all share a common process modeling language.
Second, unlike flowcharts created in a tool like Visio or Powerpoint, the meaning of each BPMN shape and symbol is quite precise - it's defined in a specification - and in principle independent of the personal interpretation of the person who drew it. I say "in principle" because it is possible to violate the rules of the BPMN specification, just like it is possible to write an English sentence that violates accepted rules of grammar or spelling. Nothing drastic happens in that case, but the diagram's effectiveness at communication is decreased.
Third, BPMN is a language shared by business and IT, the first process modeling language able to make that claim. When BPMN was first developed about 10 years ago, the only available process modeling standards at that time - UML activity diagrams and IDEF, among others - were rejected as "IT standards" that would not be accepted by business users. To business users, a process diagram looked like a swimlane flowchart, widely used by BPM practitioners but lacking precise definition in a specification. BPMN adopted the basic look and feel of a swimlane flowchart, and added to it the precision and expressiveness required by IT. In fact, that precision and expressiveness is sufficient to drive a process automation engine in a BPM Suite (BPMS). The fact that the visual language used by the business to describe a proposed To-Be process is the same as the language used by developers to build that process in a BPMS has opened up a new era of business-empowered process solutions in which business and IT collaborate closely throughout a faster and more agile process improvement cycle.
Even if you have no intention to create an automated process solution in a BPMS, BPMN diagrams can reveal information critical to process documentation and analysis that is missing in traditional swimlane flowcharts: exactly how the process starts and ends, what each instance of the process represents, how various exceptions are handled, and the interactions between the process and the customer, external service providers, and other processes. The rules of the BPMN specification do not require these elements, but use of best-practice modeling conventions in conjunction with a structured methodology can ensure they are included. My book BPMN Method and Style and my BPMessentials training of the same name are based on such an approach.
So yes, there is a cost to adopting BPMN, whether you are moving from casual tooling like Powerpoint or Visio flowcharts or from a powerful but proprietary language like ARIS EPC. There is a new diagram vocabulary to learn, diagramming rules, as well as the aforementioned conventions and methodology such as Method and Style. But the benefits of speaking a common process language are tremendous. The investment in process discovery and analysis is far more than the cost of a tool or the time required to draw the diagrams. It involves hundreds of man-hours of meetings, information gathering from stakeholders, workshops, and presentations to management. The process diagram is a distillation of all that time and effort. If it cannot be shared across the whole project team - business and IT - or to other project teams across the enterprise, now or in the future, you are throwing away much of that investment. BPMN provides a way to share it, without requiring everyone to standardize on a single tool.