Process Modeling
Process Modeling
Process modeling is the discipline of representing how work actually flows - who does what, in what order, with which inputs, decisions, and outputs - in a form others can read, critique, and (increasingly) execute. The exam tests whether you can pick the right notation and level of detail for a stated purpose, apply BPMN 2.0 correctly, and judge model quality. Expect scenario items: which gateway, which level, what is wrong with this diagram.
Choose notation by purpose, not habit
- BPMN 2.0 - the standard for detailed, potentially executable models. Core palette: pools (organizations) and lanes (roles), events (start, intermediate, end), activities (task, subprocess), gateways (exclusive XOR, inclusive OR, parallel AND, event-based, complex), sequence flows inside a pool, message flows between pools, and artifacts such as data objects and annotations.
- SIPOC - six-column scope view (Suppliers, Inputs, Process, Outputs, Customers) used to frame a process before detailing it.
- Value stream map - adds time and value-added/non-value-added flags; use it when lead time is the question.
- EPC and UML activity diagrams - event-driven and object-oriented alternatives; know what each emphasizes rather than reciting syntax.
Levels and hygiene
Level 0 is the value chain, Level 1 the process groups, Level 2 the end-to-end process, Level 3+ subprocesses and tasks. A model is sound when each path has one unambiguous start and end, activities are named verb-noun ("Verify credit"), events are named as states ("Credit verified"), every split is closed by a join of the same type, XOR/OR splits carry conditions, and genuinely exceptional paths have default flows.
Worked example
Order fulfillment: after "Check credit," an exclusive gateway sends rejected orders to an end event and approved orders onward. Pick/pack and invoice creation both run - an AND split - and shipping cannot start until both finish, so an AND join precedes "Ship order." Reasoning: XOR because exactly one outcome holds; AND because the two activities are concurrent and both are prerequisites. An inclusive gateway here would wrongly admit "pick only" as a valid instance.
Traps that cost marks
- Reading inclusive OR as either/or; it permits any combination of true conditions and its join must evaluate them.
- Drawing sequence flows across pools - cross-organizational handoffs are message flows.
- Modeling only the happy path and hiding rework loops.
- Mixing levels: a task-level diagram labeled as a Level 1 process map.