The Current State of Model Based Definition

2019

The Engineering drawing has stood as the universal method of translating design intent since the first standard was formalized in 1927 as BS308. Further development of national and international standards has been informed by advances in CADCAM technology and the need for transfer of complex yet unambiguous definition between organisations. The emergence of model based definition (MBD) has driven a new workflow where the engineering drawing is no longer required. Instead, the dataset includes semantic, machine readable, tolerancing of surfaces and features for integration into manufacturing and metrology procedures. Despite the advantages of MBD, it has been largely ignored in UK Higher Education. However MBD is the ideal method for teaching and learning geometrical tolerancing since it ignores the theoretically exact dimensions and housekeeping, concentrating on the functional limits. Further, it utilises the 3D workspace that students are increasingly familiar with.

Computers in Industry, 2010

The Model-based Definition (MBD) approach is gaining popularity in various industries. MBD represents a trend in Computer-aided Design (CAD) that promises reduced time-to-market and improved product quality. Its main goal is to improve and accelerate the design, manufacturing and inspection processes by integrating drawing annotations directly onto a 3D model, therefore obviating the need to generate engineering drawings. However, its implementation throughout the whole product lifecycle has not yet been fully adopted. Traditional engineering drawings still play an essential part in the capture and distribution of non-geometric information. Based on thirty-four interviews conducted within the Engineering, Drafting, Configuration Management, Airworthiness and Certification, Manufacturing, Inspection and Knowledge Management departments from two Canadian Aerospace companies, the objective of this paper is to report on the main barriers that need to be overcome in order to fully implement the MBD initiative. In addition, the necessary elements and specific requirements needed to evaluate the capacities of emergent tools are proposed. ß

2011

3D Model-Based Engineering (MBE) is an approach to product design, manufacturing, and support where a digital three-dimensional representation of the product serves as the normative source for information communicated throughout the product's lifecycle and supply chain. MBE simplifies data management and provides a more powerful communication medium than 2D-based environments. Lightweight formats, offering a low-cost way for humans to view and potentially for applications to consume geometry and Product Manufacturing Information (PMI), are a critical component of MBE and enable collaboration without requiring that business partners buy expensive Computer-aided Design (CAD) systems. These formats are becoming increasingly popular-and increasingly complex-as their representational capabilities grow. Their value to industry is driving a push for standardization. We discuss the advent of MBE, the standards and technologies that make it possible, and the importance-and challenges-of product data validation. NOMENCLATURE

In which phase of your PhD work are you?: I have been a scientific assistant at IPEK for the last one and a half years. The phase of research clarification is done. The next steps are to set up a suitable research design.

This chapter distinguishes two different modeling relations between vehicles and targets: design relation and representation relation. The relations are characterized by their different directions of fit. Three examples of modeling enterprises are discussed: a bioengineering model, called the "lung chip", an architectural model, called the "weekend cottage", and an engineering design model, called the "jet engine." The two modeling relations with different directions of fit are analyzed in the three examples. The lung chip is standing in a representation relation to its corresponding target and the modeling of the cottage involves a design relation to its target. The modeling of the jet engine involves both modeling relations. The first two examples also involve the other, complementary modeling relation: the protocol of the chip is standing in a design relation to the chip and the cottage model is standing in a representation relation to the design plan. With the help of these examples a basic assumption of philosophy of engineering and technology is challenged. These examples show that it is not strictly speaking true that engineering modeling is exclusively about how things should be rather than about how things are. It is shown that a representation relation is prominently involved in the first model of the lung chip. This modeling involves reasoning about how things are rather than about how things should be. So, one modeling enterprise seems to be rather about what is than about what should be. The other two examples may be seen as confirming evidence for the basic assumption. What is common to all three models is that they involve design and representation relations. 2 Keywords Models, science, engineering, direction of fit, design, representation Introduction Models are abundantly used in engineering research, in engineering design, as well as in science. In this chapter, the urge to pose a generic question about models or engineering models will be contained. It is reasonable to assume that the generic question of what models are does not allow for a simple and uniform answer (cf. Frigg and Hartmann 2012; Poznic 2017) and neither does the less generic but still ambitious question of what engineering models are. Yet, attempts to answer specific questions of how particular engineering models are used seem to fare better. For example, one can ask for which purposes particular models are deployed. A further twist to the question about models may be to focus on the practice of modeling instead of regarding models as objects, in the first instance. 1 In the following this will be the strategy of this chapter, namely to focus on the practice of modeling and to study particular instances of the uses of models as tools in different contexts of engineering. Different purposes may direct the practice of modeling. In the literature on models one finds many answers to the question about what their function is. Modeling may be practiced in order to explain (Bokulich 2017); models can be used as exploratory means (Gelfert 2016); modeling can be pursued to predict (Levins 1966); models can be used to conduct simulation studies (Winsberg 2010); they can be used as epistemic tools (Boon & Knuuttila 2009); or 4 language to the relation between vehicles of modeling and targets of modeling. 3 Pictured simply, this is about the relation between model and the thing that is to be modeled. According to this distinction, there are two relations with different direction of fit: One relation is about how the target should be according to the vehicle of modeling and the other relation is about how the target is according to the vehicle. Examples for vehicles are computational models of buildings, scale models of a bridge, mathematical models specified by equations, simulation models, etc. But also, model descriptions such as sentences in a technical language, descriptions in ordinary language, strings in programming codes and mathematical equations can be seen as vehicles among other examples. Examples for targets are the things that are modeled with the help of the vehicles, things such as buildings, bridges, human organs, jet engines, etc. The result of the application of the distinction of directions of fit is that there are two different modeling relations. With the help of this result I will show, on the one hand, what is correct about the basic assumption that engineering modeling is rather about how things should be in contrast to how things are. On the other hand, I will also show that this assumption is too simplistic, because engineering modeling is also about how things are and not only about how things should be. Beyond that, some enterprises encompass modeling relations of both sorts.