Matti Pajula Utilization of model-based definition within mechanical design and manufacturing
of master's thesis
A review of the design intent concept in the context of CAD model quality metrics
From the perspective of Computer Aided Design (CAD), Design Intent is a term commonly defined as a model’s anticipated behavior once it undergoes alteration (ex. will a cylindrical hole continue to share concentricity with a boundary arc should the dimensions be modified?). At present, a standardized manner in which to explicitly communicate or deduce a CAD model’s design intent does not exist. The design tree (feature tree or history tree) in most parametric modeling applications offers implicit depiction of design intent, but not all descriptive information is adequately conveyed (ex. a sketch concentric constraint is not recorded in the design tree and is only accessible if the requisite sketch is opened and examined). An explicit representation would be immensely more valuable, especially for models with complex geometric features or for those working in a collaborative design environment. This paper reviews current understanding of design intent, with an exploration of its relationship to Design Rationale, in the context of product models and their quality enhancement.
Defining Expertise in the Use of Constraint-based CAD Tools by Examining Practicing Professionals
Academic engineering graphics curricula are facing a rapidly changing knowledge base and current teaching and assessment methods are struggling to keep pace.  This paper is the second in a two-part series which examines practicing engineering graphics professionals to discover their experiences in developing expertise in the use of constraint-based CAD tools.  It presents the results of a knowledge-mapping task and think-aloud modeling task used with five practicing product designers to examine their solid modeling strategies used when creating a 3D model and their organization of the concepts surrounding the knowledge domain of constraint-based CAD tools.  The results of the think-aloud modeling task yielded five specific modeling procedures which were distilled into one common modeling procedure for the given object.  The results of the knowledge mapping task revealed five separate knowledge maps, and the common elements from each one were combined to form a generic knowledge map related to the use of constraint-based CAD tools.  These two sets of results comprised the initial elements used to define expertise in the use of constraint-based CAD tools based on these five participants.  This article provides an initial look at an approach to creating geometry with constraint-based CAD tools, as well as specific topics to be included in a curriculum that includes constraint-based CAD tools.  There conclusions also suggest potential teaching and assessment methodologies.