Louis Rivest

Will Model-based Definition replace engineering drawings throughout the product lifecycle? A global perspective from aerospace industry

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.

Adaptive generic product structure modelling for design reuse in engineer-to-order products

In product lifecycle management, the efficiency of information reuse relies on the definition and management of equivalence information between various product data and structure representations. Equivalence information ensures the consistency and traceability of product information throughout the product lifecycle. The sales-delivery process of engineer-to-order (ETO) products presents a great potential for design reuse, i.e. the reuse of previously validated design solutions in the design of new product variants according to customer-specific requirements. A product family data model that focuses on the interdependencies of viewpoints on information will therefore improve the setup of design reuse mechanisms such as modularity. This paper describes the Adaptive Generic Product Structure (AGPS), a dynamic structure-based product family modelling approach that enables the systematic aggregation of product variants and their distinctive components. The purpose of the approach is to capitalize on the expanding component variety developed within previous product variants as early as the sales lead phase of the sales-delivery process, in order to reduce customer-driven design costs and shorten lead-times. An illustrative example based on the aerospace industry is presented.

A Multiple Views Management System for Concurrent Engineering and PLM

Product Lifecycle Management (PLM) is an approach for controlling and exploiting product-related information throughout its lifecycle as needed by various business functions. Concurrent engineering (CE) integrates several disciplines contributing to product design. Both PLM and CE involve information sharing amongst disciplines having a specific point of view regarding the product. While each discipline exerts its own expertise and methods on the definition of the product and its related processes, information must remain consistent for all disciplines and throughout the evolution of the product definition. Therefore, being able to efficiently manage multiple views fulfilling the needs of multiple disciplines is an important issue. This article, proposes a multiple views generation mechanism incorporated in the product feature evolution validation (PFEV) model. The PFEV model is a dynamic workflow that controls the information flow needed to support a product definition evolution (PDE) while supporting its validation by all the disciplines involved. The model addresses two qualities of an information system: dispatching relevant PDE information to appropriate disciplines and providing this information according to specific views. With current CAD tool implementations, disciplines will not need all the information obtained from the numerical model, which often comes from files characterizing the geometry. Thus, each discipline must interpret the information characterizing the product by performing some filtering or adaptation in order to obtain what is relevant to its function. Two cases are associated with the views generation mechanism that corresponds to the elimination of not-useful explicit information and to the adaptation of implicit information, respectively. To accomplish this, three alternatives are distinguished to generate a view: create a new view, recuperate an existing view and update an existing view. The process used to create a new view is composed of three stages: selection of data element to be treated, selection of treatment parameters to be applied, selection and execution of views generation algorithm. The generated view is then saved in a table of views characterization, which is used to recuperate an existing view. Three reference elements (treatment parameters, views generation algorithm, and knowledge parameters) are saved when a new view is created. These elements are used for each update required for the existing view.

A Product Feature Evolution Validation Model for Engineering Change Management

Product design integrates several disciplines in a concurrent engineering (CE) environment. Each one of these disciplines has a specific point of view on the product being developed. While each discipline exerts its own expertise and methods on the definition of the product and its related processes, information must remain consistent for all disciplines and through the evolution of the product definition. This paper proposes a product feature evolution validation (PFEV) model that aims at controlling the information flow needed to support a product definition evolution (PDE) while insuring its validation by all disciplines involved. The model applies both to the product design and modification phases, i.e., before and after releasing its definition. The PFEV model thus supports CE and enables managing the product feature evolution throughout the product life cycle. The PFEV model defines an exchange protocol between the disciplines in order to preserve the consistency of the numerical model, which includes the complete numerical information characterizing the product. The model addresses two qualities of an information system: dispatching relevant PDE information to appropriate disciplines and providing this information according to specific views. This is achieved by centralizing the product numerical model and by exploiting the product’s features rather than managing product model as black boxes. Links between features are formalized in a shared product features table that is used to dynamically identify all disciplines impacted by a product feature evolution (PFE). A PFE is also characterized by its potential impact, detrimental or beneficial, on every discipline previously identified as impacted. In the case of a detrimental impact, the discipline is asked to validate the evolution. If the impact is beneficial, the discipline is simply notified about the evolution. Specific views are generated for the impacted disciplines based on feature filtering and adaptation mechanisms.

PLM-based approach for Assembly Process Engineering

The paper presents a methodology in the field of Design for Assembly (DFA) related to the Assembly Process Engineering (APE) and the Product Lifecycle Management (PLM). This method has been designed to develop assembly methods into a legacy web-based PLM prototype. It takes into consideration assembly constraints in the early phases of the product development process in compliance with concurrent engineering challenge. A racing car ground-link system from an experimental case study is introduced to illustrate the proposed approach.

Maintaining consistency between CAD elements in collaborative design using association management and propagation

The complete definition of a product often requires the collaboration of various partners. Data sharing and exchange between partners has thus become an important task throughout a products entire life cycle. Even while subsets of the product definition are exchanged (as work packages) and modified by various partners, the global product definition must remain consistent. This paper focuses on maintaining consistency between Computer-Aided Design (CAD) work packages and the global product Digital Mock-Up (DMU). The approach is designed to ensure better management of the associations between objects when a work package is extracted from the global DMU, modified by a partner, sent back to the originator and then re-inserted into the global DMU, which must be modified in turn so as to maintain consistency. To this end, we propose an association management model for the digital mock-up (Digital Mock-up Association Management Model, DMU-AMM) that transposes the associations that exist between a DMU and a work package, including package extraction and modifications, to ultimately guide the evolution of the DMU so as to reconcile the associations between a modified DMU and the modified work package and there by maintain consistency.

Dynamic product modeling with inter-features associations: Comparing customization and automation

AbstractThe customization of CAD tools and the development of trade-oriented applications make it possible to eliminate tedious tasks of modeling that would otherwise monopolize the time of designers. This article reviews some concepts, such as entity typifying, associations, imprints and pseudo-imprints, used to associate features to form a dynamic product model. Concepts are tested in an aerospace case-study where CAD tools are used for modeling pockets in aircraft skin panels. Specific companies’ know-how can be modeled by CAD tools through either Customization or Automation. Customization is achieved by implementing the concepts through User-Defined Features (UDF). A UDF is seen as a specific aggregation of constraints established between lowlevel geometrical objects, so as to transform an imprint into a pseudo-imprint. Once defined, this aggregation of constraints is manipulated as a single entity to accelerate design work. Automation goes beyond customization by performing UDF instantiation with lim...

An innovative software architecture to improve information flow from CAM to CNC

Abstract Over the years, machine tool evolution has allowed faster equipment, using new configurations, to manufacture parts that were almost impossible to machine in the past. Despite this tremendous evolution in machine and control technologies, the metalworking industry is still using the old ISO 6983 G-Codes programming interface to control the motion of these machines. This programming interface is not the most flexible or most appropriate for use by new open-architecture machine controllers and object-oriented high-level machining interfaces such as ISO 14649 (STEP-NC). This work proposes an innovative language, the ‘Base Numerical Control Language (BNCL),’ which is based on a low-level simple instruction set-like approach. The architecture is designed around two concepts: the BNCL virtual machine, which acts as a virtual microprocessor, and the BNCL virtual hardware, which is an abstraction of the machine tool. The language is characterised by its simplicity and flexibility, two qualities that are critical in a market in which the capabilities and performance of machines are constantly improving. The proposed architectural concepts are validated through various computer simulation and physical tests, including performance throughput, trajectory driving, and CNC controller extension capabilities.

Product data reuse in product development: A practitioner's perspective

Although much PLM implementations and research have focused Q1Qon data storage and management, real value of data is achieved through its reuse, as data is considered to be an asset that acquires its value only by its consumption [1].The general data reuse process is described and two variants identified: 1) data reuse that results from stakeholders’ personal initiative; and 2) organization-driven data reuse. The data reuse process can lead to two positive outcomes: either the data is reused as-is or it is evolved/adapted to a new context. The data reuse process is analyzed and decomposed into a series of activities. Challenges associated with these activities are identified. Some of these challenges are analyzed so as to identify their constraints and their enablers – one of which is data spreading among multiple information systems (PLM, ERP, MPM, file systems, etc.). This paper therefore helps identify the steps toward improving data reuse.

Concurrent versioning principles for collaboration: towards PLM for hardware and software data management

The change management (CM) and version control mechanisms used in the mechanical and software domains are presented in the product lifecycle management (PLM) and application lifecycle management (ALM) approaches, respectively. Based on their comparison, this paper discusses branching/merging concepts and utilises them to propose an evolution of the product data management (PDM) functions of PLM, thereby allowing PLM to become a collaborative platform common to software and hardware engineers. This evolution is an opportunity to develop a three-way merge tool for CAD documents. Recent works on model-merging techniques from the software development domain are evaluated in the process.