As commercial airplanes continue to evolve, Boeing's product costs under the original model continue to increase and the backlog of airplanes is growing. How did Boeing design and manufacture high-performance airplanes at a fraction of the cost in a highly competitive market? Data analysis shows that there is a huge potential for development in the product design and manufacturing process, and an effective way to save money is to reduce the consumption of changes, errors and rework. A part from the completion of the design, to go through the process of process planning, tooling design and manufacturing, manufacturing and assembly processes, within this process, design accounts for about 15% of the cost, manufacturing accounted for 85% of the cost of any changes in the design of the part before the delivery of the drawings can save the subsequent 85% of the production costs.
Case Study and Practices
In the past, most aircraft development has been based on traditional design methods, with design teams divided into specialized departments and a serial development process. Large passenger airplanes take more than ten years from design to prototype, and as little as seven to eight years. Boeing in the 767-X development process using a new "parallel product definition" concept, through the optimization of the design process gathered the latest management solutions to improve the design, improve the quality of aircraft production, reduce costs, improve the plan to achieve within three years from the design of a test flight success of the The goal was to go from design to a successful test flight in three years.
Boeing's parallel design vs. traditional development
Boeing's comprehensive application of CAD/CAM systems as the basic design tool in the development of the new 767-X aircraft has enabled designers to design all the parts three-dimensionally on computers and digitally pre-assemble them to get early design feedback that facilitates timely understanding of the design's integrity, reliability, repairability, manufacturability and operability. At the same time, the digitized design files can be used by subsequent design departments*** to obtain feedback and reduce design changes before manufacturing.
(1) 100% Digital Product Design
Aircraft parts are designed using CATIA to design 3D digital graphics of the parts. Using CATIA system to design aircraft parts, it is easy to design 3D solid model, and it is easy to assemble on the computer, check the interference and fit, also can use the computer to accurately calculate the weight, balance, stress and other characteristics. Intuitive part drawings aid in the design of the appearance and can help to understand what will happen after assembly. In addition, sections can be easily obtained from solids; parts can be machined on CNC machines using digitized design data to drive them; product illustrations can be created more easily and accurately; and user service groups can publish user profiles using CAD data layout techniques.
All part designs form only unique data sets that are made available to downstream users. For user-specific requirements, only the data set is modified, not the drawing. Each part dataset consists of a 3D model and a 2D drawing, and the CNC process is available to the wireframe and surface representation of the 3D model.
(2) 3D solid digital machine pre-assembly
Digital machine pre-assembly is a computer modeling and simulation of the assembly process, used to check the interference fit problems, this process is based on the design of *** enjoy. The digital pre-assembly will coordinate component design, system design (including piping and wiring arrangements), and check the installation and disassembly of components. The application of digital complete machine pre-assembly will effectively reduce the engineering changes caused by design errors or rework.
With the emergence of a new generation of digital pre-assembly software tools, the functions will include interference fit checking and selecting the best accuracy. Digital machine pre-assembly can assist the designer in eliminating interference before the drawing is sent. The designer can search and access other related design systems to check design coordination. Other design groups such as engineering analysis, materials, planning, tooling, and user assurance are also involved in the design scope and provide feedback to the designer before the drawing is released.
(3) Parallel Product Design (CPD)
Parallel product design is the study of integrated, parallel design and its related processes (including design, manufacturing, and assurance). Parallel design requires the designer to consider all factors concerning the product, including quality, cost, schedule, and user requirements. In order to fully utilize the effectiveness of parallel design, the following factors are needed:
1) Training designers in various aspects, rationally configuring design and manufacturing teams, and integrating product design, manufacturing, and assurance processes.
②The use of CAD/CAE/CAM to ensure integrated design, collaborative product design, *** enjoy the product model, *** enjoy the database.
③Use a variety of analysis tools to optimize product design, manufacturing, and safeguard the process.
Table 8-1 Comparison of Boeing 767-X development approach and traditional approach
767-X approach
Traditional approach
Engineering designers
Design and issue drawings on CATIA
Design piping, wiring, and pods using digital pre-assembly
Ensure that requirements are met using digital complete machine pre-assembly
Check and resolve interferences using digital complete machine pre-assembly
Interpolate products using CATIA
Design and issue drawings on sulphuric acid paper
Design on sulphuric acid paper
Use prototypes
Process in manufacturing
Manually draw using prototype
Engineering analyst
Analysis in CATIA
Completion of design load analysis prior to release of drawings
Analysis in drawings
Completion of qualification period
Manufacturing planner
Working in parallel with designers
Design engineering parts tree on CATIA
Build illustration plan with CATIA
Check important features to aid in software revision management
Routine sequence
Design-900 parts
Build mfg. engineering drawings
None
Works with tooling designer
Work in parallel with the designer
Design the tooling concurrently with CATIA
Use CATIA to allow mounting to check and solve interference problems
Part-tooling to allow assembly to ensure that the requirements are met
Routine sequence
Design with sulfate
Design in the production of the tooling Processing during production of tooling
Processing during production of tooling
NC programmers
Working in parallel with the designer
Generating and checking NC processes with CATIA
Routine sequence
With other systems
User services group
Working in parallel with the designer
Working in parallel with the designer
Designing all ground support equipment concurrently with drawings using CATIA Design all ground support equipment concurrently with drawings
Technical Publishing publishes information using engineering data
Parts are pre-assembled with ground support equipment to ensure requirements are met
Routine Sequence
Design on acid paper
Interpolate by hand
Generate parts/fixtures
Coordinators
Design Manufacturing Team
Various Organizations
Integrated Product Development Team
Boeing has accumulated 75 years of development experience in commercial airplane manufacturing, and has successfully launched different models of airplanes, such as the 707 to 777. In these model developments, the organizational model of product development largely determines the product development cycle. The figure below represents the evolution of the organizational model of these model developments.
The product development team for the 777 is divided into IPTs by function, such as electronic IPTs, mechanical IPTs, and structural IPTs.
IPT, as a new product development organization mode, is closely related to the cultural background and social environment of the enterprise. Here we summarize the IPT organizational structure and management mode in foreign countries as a reference for domestic enterprises to establish IPT when implementing parallel engineering.
①IPT is divided according to the longitudinal line of product structure, and according to the way of component composition of the product, IPT is a hierarchical relationship.
②The members of IPT come from each functional department, they make decisions in the development process on behalf of each part of the product life cycle, and collectively take full responsibility for the products developed by IPT. The biggest difference compared to the past way of working is that IPT members get their daily work instructions from the IPT team leader, and it encourages cross-disciplinary information*** sharing and real-time exchange, and eliminates the commonly used step-by-step review and sign-off system.
3) The IPT team leader defines the product development program, activities, roles, resources, etc. from the overall task. Relatively independent tasks are still performed separately by functional departments.
④ Functional departments are responsible for assigning the appropriate personnel to undertake the task roles defined by the IPT leader, and configuring the necessary working environment for the personnel undertaking the tasks. A role can be undertaken by more than one person as a group, and a single person can undertake more than one role.
⑤ The IPT team leader and the head of the functional department determine the performance of IPT members from task execution and daily work performance, respectively. Since functional departments provide personnel and working conditions, they must be financially supported by the management of the IPT.
6 The IPT itself and the roles in the IPT have a life cycle, and they return to the functional department after the product development task is completed. The realization of IPT's working model requires the support of a computer and network environment.
IPT includes technicians from various disciplines who play a coordinating role in product design, and the early involvement of IPT members in the manufacturing process minimizes changes, errors, and rework.
Improving the product development process
Why has Boeing adopted CAD/CAM systems over the past decade or so without significantly accelerating progress, reducing costs, and improving quality? The reason is that its development process and management is still stuck in the original level, the application of CAD / CAM system can effectively reduce the number of changes and design rework, the design process is also greatly accelerated, and the resulting benefits are far greater than the reduction of changes and rework brought about by the direct benefits. Boeing 767-X adopts a fully digital product design, designing a 3D model of all 767-X parts before the design is issued, and completing the digital pre-assembly of all parts, fixtures and components before the issuance of drawings. At the same time, other computer-aided systems are used, such as the IDM system for managing parts data sets and issuing drawings, the WIRS system for wiring diagram design, the integrated process design system, and all the downstream data management systems for issuing drawings and bills of materials. As a result of some advanced computer aids, Boeing improved the corresponding product development process during the development of the 767-X, such as performing system design analysis before issuing drawings, building 3D part models on CATIA, performing digital pre-assembly, checking interference fit, increasing the number of feedbacks in the design process, and reducing major rework between design and manufacturing.
Several major design processes are described below.
(1) Engineering design and development process
The design and development process begins with the creation of a 3D model, which is an iterative cycle. Designers use digital pre-assembly to check the 3D model and refine the design until all parts fit together to meet the requirements. Finally, part drawings, part assembly drawings, and general assembly drawings are modeled, and 2D graphics are completed and sent out. The design and development process needs to be coordinated by the design and manufacturing team.
(2) Digital complete aircraft pre-assembly process
Digital pre-assembly utilizes CAD/CAM system to perform assembly simulation and interference checking about 3D aircraft parts model, determine the spatial location of the parts, and create temporary assembly drawings as needed. As a complement to the digital pre-assembly process, the designer receives feedback from engineering analysis, testing, and manufacturing. Data management of the digital pre-assembly model is a large, laborious task that requires a dedicated digital pre-assembly management team to ensure that all users can easily access and make final checks before issuing drawings.
(3) Digital Prototyping Process
The 767-X utilizes a CAD/CAM system for digital pre-assembly, and the digital prototyping process is responsible for each part design and prototype installation check.
(4) Area Design (AM)
Area Design is a comprehensive design process for aircraft area parts, which uses the digital pre-assembly process to design various models of the aircraft area. Area design not only parts interference check, but also includes clearance, parts compatibility, packaging, system layout aesthetics, support, important features, design coordination. Area design is the responsibility of each design group or design and manufacturing team member, and each engineer, designer, planner, and tooling designer should be involved in area design. Area design is the task of each member of the design group or design and manufacturing team, and its completion requires the full cooperation of the design group, the structure room, and the design and manufacturing team.
(5) Design and Manufacturing Process
The design and manufacturing team consists of technicians from various disciplines, who play a coordinating role in product design to minimize changes, errors and rework.
(6) Comprehensive Design Check Process
The comprehensive design check process is used to check the correctness of the analysis of all designed parts, part trees, tooling, and CNC surfaces. The integrated design checking process involves the design and manufacturing team and the relevant quality control, materials, user services, and subcontractors, and is generally carried out at the drawing issue stage. The personnel involved check the situation periodically and recommend changes where they do not make sense. Integrated design checking is part of the design and manufacturing team's tasks.
(7) Integrated Program Management Process
Integrated Program Management is a process that increases the speed of contact, develops manufacturing process plans, testing and aircraft delivery plans. The integrated program management process not only develops a number of dedicated process plans, but also synthesizes various plans for the entire development process. The management of integrated plans will improve the visibility of the overall program.
Using digital methods and tools such as DPA to identify various downstream problems as soon as possible in the early stages of design
Digital Complete Assembly Pre-assembly (DPA) is a computer-simulated assembly process that utilizes a model of the part in each level according to the requirements of the designer, analyst, planner, and tooling designer. The parts are in 3D solid form for interference, fit and design coordination checking. By utilizing the entire pre-assembly process, all interferences throughout the aircraft can be detected and reasonably resolved. The Boeing 757 has 46 segments between stations 1600 and 1720, with about 1,000 parts, which need to be accommodated in 12 CATIA models for digital pre-assembly.
Using the digital pre-assembly process, engineering verifies that all design interferences are free and all fits are good, which results in minimal process changes. Datasets cannot be released without final approval, and this final check reduces risk and guarantees no part interference after release.
Digital machine pre-assembly is the process of modeling and simulating assemblies on a computer to check for interference fit problems, and this process is based on design*** enjoyment. The application of digital pre-assembly will effectively reduce engineering changes caused by design errors or rework. As a new generation of digital pre-assembly software tools becomes available, its functionality will include interference fit checking to select the best accuracy. Digital complete machine pre-assembly can assist the designer in eliminating interference before the drawing is issued. The designer can search and access other related design systems to check design coordination. Other design groups such as engineering analysis, materials, planning, tooling, user assurance, etc. are also involved in the design scope and provide feedback to the designer prior to the release of the drawing. Digital complete machine pre-assembly will coordinate part design, system design (including piping and wiring layout), and check part installation and disassembly.
Massive application of CAD/CAM/CAE technology to achieve drawing-less production
(1) Adoption of 100% digital technology to design aircraft parts
Digital design of aircraft parts adopts CATIA to design 3D graphics of parts. Using this system, aircraft parts can be easily designed as a 3D solid model, and it is easy to assemble on the computer, check the interference and fit, can also use the computer to accurately calculate the weight, balance, stress and other characteristics. Intuitive part drawings aid in cosmetic design and can help to understand what will happen after assembly. In addition, sections can be easily obtained from solids; digitized design data is used to drive CNC machine tools for machining parts; product illustrations can be created more easily and accurately; and user service groups can publish user profiles using CAD data wrangling techniques.All parts in the 767-X are designed using digitization techniques, and all part designs form only a unique dataset, which is provided to downstream users.
(2) Establishment of a Parts Library and Standard Parts Library for Aircraft Design
Minimizing new part designs can result in significant cost savings. Based on this realization, a large number of parts libraries were established in the development of the 767-X, including terminal blocks, angles, brackets, etc. The parts libraries are stored in the CATIA system. The parts library is stored in the CATIA system and coordinated with the standard parts library, so designers can easily find the parts library. Making full use of the existing parts library resources can effectively reduce the cost of parts design, process planning, tooling design, NC machining programs and so on. The standard parts library includes fasteners, washers, connectors, gaskets, bearings, pipe fittings, pressure plates, etc. These standard parts are stored in the CATIA standard library. Designers can select the required parts directly from the standard parts library.
(3) Engineering Characteristics Analysis with CAE Tools
Stress Analysis: Technicians directly use 3D digital parts models to perform design stress calculations, load data analysis and component safety system calculations.
Weight analysis: analysts use the 3D digital part model for weight analysis, which can obtain accurate part weight, center of gravity, volume, and moment of inertia. When carrying out the assembly of the whole machine digital model, analysts can track the assembly of the weight and center of gravity of each part.
Maintainability analysis: designers should also consider the space requirements of the aircraft's structure and systems during aircraft maintenance, and design the corresponding maintenance port cover to ensure smooth maintenance. This step is completed during the digital design.
Noise control engineering: the use of detailed drawings of the aircraft shape for aircraft shape identification and noise data analysis, the results of which are transmitted to the relevant designers. This process is accomplished on the Apollo workstation, a computerized tool.
(4) Computer-Aided Manufacturing Engineering and NC Programming
The computer-aided manufacturing process improves the engineering design by providing producible inputs and adding additional information to the database to meet part and final assembly requirements. NC programmers use CATIA tools to perform CNC programming of part wireframes and surfaces before engineering drawings are issued, and simulate the CNC machining process on the computer when necessary, thus reducing design changes, scrap and rework, and shortening the development process.
(5) computer-aided tooling design
Tooling designers use the 3D part model provided by the designer to design the 3D solid model of the tooling or 2D standard tooling, to ensure that the parts benchmarks, the computer system will store the relevant tooling positioning data. At the same time to establish the digital pre-assembly system of the tooling, the use of 3D digital dataset simulation to check the interference and fit between the part - tooling, tooling - tooling. The tooling dataset is provided to downstream users, such as tooling plan for tooling classification and manufacturing plan, NC tooling program is provided to NC dataset, which is used for NC research and certification or for workshop production.
Assisting parallel design with a megacomputer-supported product data management system
To take full advantage of the effectiveness of parallel design and to support the design and manufacturing teams in integrated product design, it is also necessary to have the support of a product data management system covering the entire functional department to ensure that the product design process is carried out in a collaborative manner and that the product models and databases are enjoyed***.
The 767-X utilizes a large, integrated database management system to store and provide configuration control over multiple types of relevant engineering, manufacturing and tooling data, as well as graphic data, drawing information, profile attributes, product relationships, and electronic check words, while providing integrated control over the data received.
Management control includes the processes of product development, design, planning, parts manufacturing, part assembly, final assembly, testing, and shipping. It ensures that correct product graphic data and descriptive content is sent to the user. Through the product data management system for digitized information *** enjoyment, to achieve the specialization of data, *** enjoyment, sending graphics and control.
The traditional method of issuing drawings will include a number of drawings and bills of materials of the parts drawing from the engineering design department to the manufacturing department, each drawing contains one or more parts, and has a unique drawing number, the drawing of each part also has a corresponding drawing number. Each model designed using digitized products has a complete part number so that graphics can be tracked and checked as they are issued.
Benefit analysis
The effective use of parallel design technology will bring the following benefits:
①Improve the quality of the design, greatly reducing the design changes in the early production;
②Shorten the product development cycle, and compared with the conventional product design, parallel design significantly accelerates the design process;
3 Reduce the manufacturing cost;
④ optimize the design process, reduce the scrap and rework rate