Hugh Dubberly on why modeling is important for designers:
As designers increasingly focus on systems and communities of systems, we need to improve our modeling skills.
Without modeling, system design is not possible. Often service systems and computer-based applications are partly hidden or invisible, or they stretch across time and space and cannot be seen all at once or from a single vantage point. In such cases, models must stand in for systems during analysis, design, and even operation.
Using models, designers can unify otherwise separate artifacts and actions. Interaction models unify interface widgets. Service models unify customer touch points. Brand models unify messages. Platform models unify individual products.”
As is usual with Mr. Dubberly, the whole article is comprehensive and lucid. Worth your time.