Showing papers on "Product design specification published in 1992"

The Mechanical Design Process

Abstract: 1 Why Study the Design Process? 2 Describing Mechanical Design Problems and Process 3 Designers and Design Teams 4 The Design Process 5 Project Definition and Planning 6 Understanding the Problem and the Development of Engineering Specifications 7 Concept Generation 8 Concept Evaluation 9 The Product Design Phase 10 Product Generation 11 Product Evaluation for Performance and the Effects of Variation 12 Product Evaluation for Cost, Manufacture, Assembly, and other Measures 13 Launching and Supporting the Product Appendixes A Properties of 25 Materials Most Commonly Used in Mechanical Design B Normal Probability C The Factor of Safety as a Design Variable D Human Factors in Design E TRIZ F Belief Map Masters

Purchasing's Role in a Concurrent Engineering Environment

Abstract: Purchasing's Role in a Concurrent Engineering Environment In this article, early purchasing involvement in the design and development of a product is examined. Purchasing impacts are effective when they are an integral part of a concurrent engineering environment. In this environment, planned purchasing contributions, along with a number of other factors, are included in the early stages of new product design. The article proposes and explores potential areas of collaboration between purchasing and design. The areas of collaboration include, but are not limited to, developing specifications, interchangeable parts, part standardization and simplification, value analysis, part substitutions, part exclusions, and a variety of other miscellaneous areas. INTRODUCTION The concept of concurrent engineering, in its broadest sense, is viewed as a manufacturing strategy capable of providing the American manufacturing system with a competitive advantage in the world marketplace. Concurrent engineering has been defined in various ways. Each definition is largely the reflection of an individual's background and experience. Vasilash suggests terms such as simultaneous engineering, life cycle engineering, process driven design, team approach, and design for manufacture.[1] Other terminologies, such as concurrent design, Unified Life Cycle Engineering (ULCE), and parallel engineering, have also been used. Whatever the definition, the concept concentrates on the simultaneous consideration of the downstream product development activities, as opposed to their consideration on a sequential and isolated basis. Concurrent engineering, therefore, calls for the consideration and inclusion of product design attributes such as manufacturability, procurability, reliability, maintainability, schedulability, marketability, and the like in the early stages of product design. The Role of Product Design in Concurrent Engineering The natural focal point of concurrent engineering is product design. A decision concerning product design tends to have a number of significant manufacturing and non-manufacturing impacts on the life cycle of the product. The following examples signify such an importance. * A study at Rolls Royce revealed that design determined 80 percent of the final production cost of 2,000 components.[2] * According to General Motors executives, 70 percent of the cost of manufacturing truck transmissions is determined in the design stage.[3] * Ford Motor Company has estimated that among the four manufacturing elements of design, material, labor, and overhead, 70 percent of all production savings stem from improvements in design.[4] * A study revealed that the product design is responsible for only 5 percent of a product's cost; it can, however, determine 75 percent or more of all manufacturing costs and 80 percent of a product's quality performance.[5] * Yet another study shows that 70 percent of the life cycle cost of a product is determined at the design stage. The life cycle cost here refers to the cost of materials, manufacture, use, repair, and disposal of a product.[6] Advantages of Concurrent Engineering The proper consideration and inclusion of design attributes early in the design process yields these advantages: * Reduction in product development cycle time * Avoidance of costly future redesigns * Reduction in duplication of effort * Better communication and dialogue * More efficient operation and higher productivity * Overall cost savings + Reduction in the number of parts manufactured + Better machine utilization time + Easier manufacturable parts + Fewer reworks and scraps + Greater use of standard features, thereby reducing tooling costs + Fewer changes in process planning * Avoidance of product recalls * Lower maintenance costs * More reliable products * Better customer satisfaction * Improved bottom-line earnings A SYSTEMS APPROACH TO CONCURRENT ENGINEERING There are two issues at the core of successful implementation of concurrent engineering. …

Modelling Product Structures by Generic Bills-of-Materials

Abstract: 1. Introduction. 2. Product (structure) data in MRP-oriented production control information systems. 3. Production control environments and bills-of-material. 4. MRP-II approach to structuring bills-of-material in environments with large product variety. 5. An architecture for product specification and bill-of-material generating systems. 6. Product specification systems and bill-of-material generating systems in literature. 7. Representing product specification data. 8. The variant bill-of-material concept. 9. The generic bill-of-material concept. 10. Set-relationships between items. 11. A conceptual database model for a generic bill-of-material processor. 12. A case study: generative bills-of-material in practice. 13. Summary and conclusions. Appendix A: Notation conventions in entity-type relationship diagrams. References. Subject index.

System design method

Abstract: A computerized design system is employed for designing product specifications for a multitude of products. This computerized design system uses an input from a user to define a series of goals and from these goals to create a data structure which is extracted from the goals. This data structure is then topologically stored in a computer memory which is then used to create a mapping between requirement specifications and a conceptual design. An output is then provided which can be used as a final design specification.

Fashion design and product development

Abstract: Design/development process design and innovation materials manufacture costs and profits operations management quality control management of the process.

Method and apparatus for cooperated design

Abstract: In order to derive optimum design specifications based on total evaluation performed on a product as a whole instead of individual design items during a process of determining design specifications involving a plurality of design items, candidates for the product specifications are selected by controlling design parameters for each of the design items in an integrated manner, computing values of a plurality of evaluation items evaluating candidates for the design specifications and performing total evaluation on all the evaluation items based on their computed values through collaboration among a plurality of design sections altogether auto-correcting all relevant design parameters quickly and relaxing as well as reassessing design constraints for a design parameter.

Product Structure Analysis for the Master Scheduling of Assemble‐to‐order Products

Abstract: Reports a new method for preparing a product structure analysis to improve the effectiveness of the master scheduling function for products that are manufactured on an assemble‐to‐order basis. This methodology for conducting product structure analysis uses relational database management software to identify common and unique material in a product structure. Highlights example results of the application of methodology.

A generic bill-of-material processor using indirect identification of products

Abstract: The industrial product market has become more demanding over the last decade. In particular, the number of product variants within a product family has increased very quickly. Therefore, the description of product variants in terms of product data and product structure has become a problem for existing production/inventory control information systems. In the first part of this paper we develop a classification for the existing solutions in the literature. In the second part we describe another solution, the generic bill-of-material, using indirect identification of products. The generic bill-of-material provides the user with a means of describing a large number of variants with a limited amount of data, while leaving the product structure intact.

User Interfaces for Geographic Information Systems: Report on the Specialist Meeting (92-3)

Abstract: This report describes the Specialist Meeting of the National Center for Geographic Information and Analysis (NCGIA) Research Initiative on User Interfaces for Geographic Information Systems . The initiative addresses human-computer interaction methods and related issues in the design and implementation of user interfaces for GISs and other geographical software packages. The Specialist Meeting (workshop) for the initiative was held in June 1991 to set and prioritize a research agenda. The discussion concentrated on conceptual issues, and on needs for evaluation and testing. Several important themes for research were identified. Development of typologies of GIS tasks and of GIS users and use types were high priority elements of the research agenda. Spatial concepts are critical to the design of user interfaces for GIS; the issue of potential trade-offs between learnability and performance for experienced users is central; experimental testing is a critical part of the research agenda, agencies and other large organizations need guidelines on how to write product specifications for user interfaces. The paper provides details for these and other elements in the research agenda regarding User Interfaces for Geographic Information Systems. The report also contains 35 position papers that were circulated to the participants before or during the meeting.

A framework for integrating manufacturing process design and analysis

Abstract: Product design and evaluation requires a broad and varied set of information and analysis tools Yet effective design and evaluation of a product during its design phase is critical if production costs are to be minimized A system is described that integrates product design specifications with material and process databases, and a simulation-based analysis module The system allows product designs to be evaluated in terms of economic and technical criteria, and to identify the best production environment

A New Design for Quality Paradigm

Abstract: SUMMARY Product development and design has a tremendous influence on the final product quality and the cost of quality. This paper presents a critical look at the position of design for quality in Western industry and academia. It is suggested that design for quality should be enhanced in the context of design methodology in order to better fit the way that products are actually designed. Finally, the paper presents new concepts, models, and a structured procedure for design for quality, that have evolved by looking at quality from the viewpoint of design methodology.

An integrated system design environment: Concepts and a status report

Abstract: In the construction of requirements specifications for a given problem, it is generally recommended that overspecification of the problem solution be avoided [1]. Such overspecification tends to distort the functionality required by suggesting implementation concepts at the outset. In order to avoid overspecification, and to provide a support environment to the specifier, a four-stage system design environment is proposed and has been partially implemented over a three-year period. The theoretical basis of this approach is explained in [2]. Our system-level specification language (DODAN) is developed in [3]. Based on this specification language, a prototype (DAA) [4, 5, 6] for supporting the requirements specification stage has been implemented. Our other protype (DARMS) addressing the module specification stage was developed in [7, 8]. In this paper, the current status of the project is described with an emphasis on the requirements specification stage.

Approaching System Level Design

Abstract: After a definition of the term System Level, different system level design activities are identified: product specification and system level modeling, system level simulation, system level analysis and partitioning, embedding into a concurrent engineering environment. These activities then are discussed in more detail with special emphasis on modeling.

Towards a requirements definition, specification and system design environment

Abstract: The authors provide an overview of techniques for the specification of complex, heterogeneous systems, i.e. microsystems or automotive control systems including hardware (analog and digital electronics, mechanical or optical actuators and sensors) and software. An approach to an integrated environment to support and control the requirement definition, specification and system design phases is described. This approach combines behavioral, functional, and data-oriented specifications based on formal languages, as well as knowledge-based concepts for the acquisition of a complete description of the goals, requirements, and constraints related to a system design project. Within this environment, existing commercial specification and system design tools have been integrated into a CAE framework and new tools have been developed to support early requirement definition, specification flow control, early validation of specification, and specification data management. >

The development of an integrated system design environment

Abstract: A four stage system design environment is proposed which includes requirements specification, hardware software separation, module specification and system integration stages from a systems integration perspective. As part of realizing this paradigm, a system level specification language, DODAN, is introduced. Based on this specification language, a prototype, DAA, is implemented which addresses the systems level requirements specification stage. Another prototype, DARMS, was implemented to experiment with the module specification stage. This four stage model is described along with experiences in implementing and working with the requirements specification and module specification prototypes. >

Specification Formulation— an Approach that Works

Abstract: With intensified global competition, the necessity to understand and interpret market needs and encapsulate these in a comprehensive product design specification is of paramount importance. While exhortations are numerous, the modus operandi for effectively doing so are less evident. This paper sets out a proven, practical, comprehensive and structured approach for processing market information, leading to the formulation of the product design specification. In so doing, a change is called for in the approach to the management of design projects.

An automated tool for specification validation: design and preliminary implementation

Abstract: A specification is complete if it carries all the information required by the user, and minimal if it carries nothing but the information required by the user. The authors have designed a lifecycle of the requirements specification phase, whose purpose is to help achieve completeness and minimality by the proper use of redundancy. In their view of the lifecycle, the verification and validation group elicits information from the user and matches it against the generated specification to check completeness and minimality. In this paper, the authors give details of this lifecycle, and present an automated system that carries out the proofs of completeness and minimality using Prolog's inference capability. >

A formal structured method for requirement specification construction

Abstract: Structured Method for Requirement Specification Construction Shaoying Liu University of York England A formal structured method for requirement specification construction called FSMRSc is described in this paper, FSMRSC extends DeMarco data flow diagrams with the mathematical notation VDM (Vienna Development Method). Specifications constructed using this method are comprehensible, structured and formal. The significant progress presented in this paper is to develop a systematic approach to correctness proofs of requirement specifications.

Design with spatial relationships and tolerance specification and propagation for a product modeler

Abstract: In designing a product, the product specifications are developed first which conceptually constrain the geometry and functions of the product. Subsequently, its components are designed with the form in mind to achieve the functional requirements according to the specifications required. Conventional CAD systems are made for generating the geometric form of a part. This is meant to take the place of manual drafting. However, a system such as this is incapable of capturing the non-geometric aspects of the designer's intent in a form that can be used for automatic process planning. The result is that tolerance, parts relationships, surface finish, etc. cannot be specified by the designer in the CAD environment unless some form of annotation is provided. Product Modeler (ProMod) provides a concurrent product design environment for designers to assign the product specifications onto the parts' nominal geometry through Spatial Relationships Engine. With this information, the detailed design requirements, such as, tolerance and surface finish are generated by Dimensioning and Tolerance Propagation Engine. Based on the functional requirements, the features of individual parts are extracted through a Form-Function Interpreter Engine, and are then, mapped to the Form and Function database to establish manufacturing specifications such as machines and tools selection. Design Evaluator evaluates the machinability and asemblability of features in accordance with the Design Rules, machine capability and geometric interference. Design Advisor provides a way of incorporating modifications to improve the design. Design Simulation Unit formulates the problems which come from prototype design experiments. These results are then submitted to a design evaluator for further evaluation. When the iterative design procedures have been completed, the information, Topology Model, Geometry Model, Dimension and Tolerance Model, Form-Function Model, Form-Feature Model, etc. are then created for generating the process plan. In this dissertation, a sub-unit of ProMod is developed for dealing with product design. Product specifications are assigned using spatial relationships while the components of a product are assembled together on ProMod. This will involve the development of Spatial Relationships Engine, Dimensioning and Tolerance Propagation Engine as well as integrating them firmly within the ProMod architecture.

Method and device for deciding whether production of iron and steel production is possible or not

Abstract: PURPOSE:To decide whether production is possible or not by determining the analogous standards to satisfy the prescribed conditions for the information on the new product specifications to be decided, determining at least a part of the conditions for the material tests of the specification information included therein according to the contents of the above- mentioned information on the new product specifications and the contents of the above- mentioned analogous standards and contrasting the resulted final specification information with the information on the past results. CONSTITUTION:Whether the production is possible or not is basically decided by utilizing the actual data on the past ample standard products in this invention. Namely, the standards analogous with the new standards are selected and the product specifications necessary for the decision are determined on the basis of the specification data relating to the selected analogous standards. However, if the conditions of the specific material quality tests of the analogous standards and the new standards vary, the specifications of the analogous standards are adopted in place of the new standards as the product specifications for the decision of this part. Decision is made that the production is possible if the production record of the material quality level stricter than the product specifications to be decided exists for the past results of the conditions on the material quality tests equal to the conditions for the material quality tests for the product specifications determined in such a manner.

Product definition through the design-by-use process

Abstract: To promote product quality, a design process should represent the needs of all who will use, develop, or modify the product. The service creation environment (SCE) for the A-I-Net™ adjuncts, a family of products that allow service providers to control the definition, development, and evolution of advanced intelligent network services, was developed with a design-by-use process. This process is an iterative cycle of analysis, prototype construction, and user evaluation. It uses human factors and system prototyping techniques to involve potential users of the product early in the product definition and design stages.

The Selection of Surfaces in Inspection Planning for Coordinate Measuring Machines

Abstract: If probe paths for coordinate measuring machines are to be generated automatically then methods must be developed that can determine which surfaces need to be inspected. Evolving computer based systems supporting engineering design and manufacture are adopting the concept of a Product Model as the central source for the data required by the various activities in the design and production cycle. This paper outlines a product model capable of representing data relating to a component’s geometry, dimensions, specification and manufacturing processes. An inspection planning application then uses the product model to determine which surfaces need to be inspected to ensure that the product conforms to the product specification.

Categorisation of design information in terms of design process and product specifications for a standard for computer representation of specifications

Abstract: Design information is categorized in this paper in terms of boththe design process and product specifications, as a basis for computer representation of specifications. This requires improved definition of standard specification and product structure, as well as information handling in design checks. A computer representation of specifications for interactive design use and data exchange is described using theconceptual framework outlined. It is based on symbolic graphical representation of specifications linked to screen windows containing text and computations. Some requirements of a standard for computer representation of specifications are outlined.

Introduction to Concurrent Engineering: Electronic Circuit Design and Production Applications

Abstract: : This document presents an overview of Concurrent Engineering (CE), i. e., the use of Multi-discipline Design Teams to perform the simultaneous design of the product and the process to produce the product. The intent is to encourage product developers, from the outset, to consider all elements of the product life cycle from conception through disposal, including quality, cost, schedule and the user requirements. The document also explores a number of specific tools which may be used to assist the reader in the implementation of CE. Concurrent engineering, Multi-discipline design teams, Product life cycle, Robust design, Automated design tools, Design, Development, Production.

Developing a pharmaceutical purchasing strategy.

Abstract: The process commonly used by group purchasing organizations to contract for multisource pharmaceuticals and a strategic approach for the director of pharmacy in working with the purchasing group and the P & T Committee is described. The pharmacist should be knowledgeable concerning the group's contract commitment requirements, product specifications, terms and conditions and procedures for vendor selection, product award, contract implementation, and performance monitoring. To ensure results that meet the needs of the medical staff, it is important that the P & T Committee actively participate. The P & T Committee should understand the reasons for selecting a particular purchasing group, understand the necessary steps in obtaining the most favorable economic advantage, review products with potential brand interchange concerns, recommend product specifications, and reaffirm formulary procedures regarding the principle of current consent.