I use a domain model to describe phenomena in an application domain. For example, I map the main business objects. Then I show their relationships. Thus I understand the environment where a planned system will operate. Moreover, I use domain models to clarify terms for stakeholders. In addition, I reduce ambiguity early. Therefore I improve requirements quality.
First, I decide the purpose of the model. Next, I choose the view and diagram type. For instance, I pick a class diagram for static structure. Alternatively, I pick a scenario or story model to show interactions. Specifically, static domain models specify objects and their associations. By contrast, domain story models show visual stories of how actors interact with devices, artifacts, and other items. Consequently, I cover both structure and behavior when needed.
I select a modeling language. I check its syntax, semantics, and pragmatics. Then I use the defined modeling constructs. For example, I use class and association constructs in a class diagram. Likewise, I add textual supplements when a diagram alone cannot express a trigger or a rule. In practice, graphical elements and textual elements form the atomic constituents of a model. Therefore I always combine diagrams and text where helpful.
I keep the model conceptual and abstract. Thus I reduce reality to what matters. I apply descriptive modeling when I document the current situation. Alternatively, I apply prescriptive modeling when I show the intended future state. In either case, I name the original that I model. Then I state whether I describe existing reality or prescribe a new one. This clarity helps testers, developers, and stakeholders.
I manage model quality actively. First, I ensure syntactic quality by using the modeling language correctly. For example, I avoid misusing model elements. Otherwise, stakeholders may misinterpret the model. Second, I check semantic quality by ensuring the model matches the intended meaning. In addition, I validate the model for pragmatics. For instance, I make sure the model serves its intended purpose for the target audience. Consequently, I reduce the risk of wrong tests or wrong implementations.
I use views to keep complexity manageable. For example, I create context models to show system boundaries. Then I create more detailed views for specific concerns. In addition, I reuse standardized modeling languages like UML when appropriate. However, I remain careful. If stakeholders do not master the language, a diagram may not help. Therefore I provide explanations and training when needed.
I involve stakeholders early. First, I review the domain model with domain experts. Next, I refine terms and relationships. Moreover, I run small scenarios to validate domain story models. Then I update the static model accordingly. In this way, I keep the model accurate and useful.
Finally, I use domain models to guide requirements engineering. Specifically, I use them to derive requirements, to define scope, and to support verification. Overall, I keep sentences short. Consequently, automatic translation works better. In summary, I create clear, purpose-driven domain models that describe the application domain, show structure and stories, and support the development of correct systems.