Manufacturers worldwide are moving to a new business strategy "Lean Manufacturing." The term Lean implies "Quick and Agile." The Product Development Goal in Lean manufacturing, is to acquire the ability to design and produce a wide variety of high quality products, designed for todays market, manufactured to specific customer orders, at lower prices, and delivered within extremely short lead times. To achieve this goal requires short cycle product design, enhanced by a cross-functional "Team" approach to product development.
Customers now expect immediate, global availability of customized products. Therefore, manufacturers and suppliers must meet demand for customization, changes in quality, custom packaging, and tight delivery schedules. Manufacturers' migration in the late 80s, and 90s towards just-in-time production were only a start. Most now want to take JIT (Just-in-time) further, toward "Lean manufacturing", running production with only essential resources, and minimizing work in progress and all stocks of either raw materials or finished goods. Supplier relationships are now identified by collaboration in product design, inventory management, and joint partnering on new product development. Supplier relationships are so important to manufacturers adopting these strategies that many manufacturing enterprises would cease to exist without them. World-class companies have evolved their supply-chain management practices from the adversarial, lowest cost model to supplier partnerships, closely coordinated production scheduling, "just-in-time" delivery, and Web enabled collaboration.
When reviewing conditions present within the current manufacturing environment, it is apparent why the shift from traditional 2D Drafting (CAD), to the next generation 3D Solids Modeling is strategic business issue for manufacturers. Simply stated, the 3D Solid Modeling environment enhances both the utility of computers and software, as well as the productivity of all individuals involved within: management, customers, suppliers, engineering, manufacturing, purchasing, document writers, and field personnel.
Understanding 3D Solid Modeling
When planning the evolution to a 3D-design environment, one needs to understand the importance of the solid model. In the 2D world, drawings are continually reinterpreted throughout a product's life cycle. Pull a drawing, make changes, create a new drawing, give the new drawing a new identity
. With 3D technology, the solid model is the key element. 2D drawings are just a different way of representing the model. A 3D solid model may be tested throughout a design process, using tools like: finite element analysis, and motion analysis. In short, 3D solid models enable faster understanding of a new product design, eliminating physical prototypes, and reducing product development cycle time.
Lean Manufacturing issues driving the migration from 2D to 3D Solid Modeling
The migration from 2D drafting to 3D solid modeling center primarily around three emerging corporate competitive positioning strategies: time to market cycle reduction, collaboration, and quality.
The first strategy, time to market cycle reduction, has been receiving increasing amounts of attention lately as the competitive environment within manufacturing intensifies. History has proven that time to market cycles can only be reduced by dramatically enhancing how information is processed and utilized within an organization. Therefore, the overriding goal is to maximize information availability and usage. The rate of information usage within organizations can be increased by two means: by simplifying understanding of the information provided, and making information simultaneously available to more people, thus adding more resources. 3D solid models represent a significant enhancement over 2D drawings in presenting design information, making the design understandable, thus, available to more people.
The strategy of fully utilizing the power of computers and software is the cornerstone of the two most common time to market reduction methods: Continuous improvement (re-engineering), the elimination of non value-added process steps. Concurrent engineering, where "project teams" from within and outside an organization, work on a project simultaneously, as opposed to the traditional sequential process approach. In most cases this includes both the supplier and customer. Only with the power of computers, and 3D solid modeling software, can such efficiencies in organizational processes be achieved.
The second strategy is quality. Quality in todays terms has a much more encompassing meaning than just a few years ago. In a global economy, the quality definition applies to the aggregate processes, decisions, and services inherent within the corporation, in addition to the final product.
The terms associated with this new approach to quality are design envelope, process capability, and six-sigma. Design envelope represents product performance decisions established during initial product development. Process capability represents the measure of actual design and process performance during the product life cycle. Six Sigma, a statistical term, is a bell shaped distribution, where design tolerance limits are at a distance of six sigma from the center, indicating the typical deviation from the average of a measured quality characteristic.
The grounding for this new quality definition is the emphasis on accurate information generation, (including defect identification) through out the process, and the subsequent clarity of the information exchanged between all the various points within the process, the most important being feedback of process information to design and process engineering.
In the case of a manufacturing company, the driver for the whole entire production process, directly following a sales order, is the information generated in engineering. Information from engineering is utilized by purchasing, manufacturing, customers, suppliers, field installation, and technical writing departments. Any inaccuracies in bill of materials, drawings, or calculations eventually show up downstream in the following forms: lost productivity, missed schedules, unhappy customers, and departmental finger pointing. To further amplify the problem: in the typical 2D drafting oriented company, each department which handles the information operates on it with a different set of tools. The majority inaccuracies which surface from information within 2D drawings, emanate from the following four sources:
Failure to accurately construct all three views on a drawing, because geometry created within one view has no implied relationship to either of the other two views. Most 2D drawings do not contain sufficient information to build a physical model without some modification from the final builder.
Failure to update all three views of a drawing (detail and assembly drawings) once one view has been modified.
Failure to update a drawings overall detail, layout, or bill of material, once any of the three has been changed.
Failure to visualize and subsequently correct interference points within assemblies.
The above characteristics are inherent to the 2D drafting environment, therefore, one can assume that a certain amount of the information generated within a 2D drawing, at the engineering level is flawed, leading to downstream quality, production, and productivity problems.
Advantages of 3D Solid Modeling over 2D drafting in a Lean environment.
Bi-directional Associative Design - Assembly drawings, details, and bill of materials are all electronically "connected". Change a drawing or a detail, and the remaining two documents update automatically. This single advantage has been proven to dramatically reduce error creation at the initial engineering point. In the 2D drafting environment, a single accurate geometric change to one portion of an assembly can require up to (6) different views on two separate drawing and a bill of material to be updated manually. Consider what level of workload is created, when a new design created in a 2D-drafting environment, arrives at the assembly station for the first time.
Intelligent Geometry - The geometry, as created by the engineer is in a format that allows other departments: design analysis, purchasing, machine shop, assembly, and technical writing to readily easily use the information. File transfers and repetitive data entry issues, as well as all of the associated problems are eliminated. It is because of the intelligent nature of the geometry, which the designer originally created, that allows for the part to be drawn only once, not three or four times which is typical in a 2D drafting environment.
Integrated Functional Solutions - The basic interface screen for the designer, stress analyzer, CNC programmer, and manual writers are all the same.
Single Database - Since all departments effectively operate on the same model, there is no need to maintain a separate drawing database for each department.
Visualization - 3D Solid Models allow engineers, managers, customers, purchasing agents, assembly personnel, salesmen, machinists, and field installation personnel to call up a drawing, and manipulate a virtual model in real time, to gain a deeper understanding of its design and functionality. This significantly reduces design evaluation to approval time.
Parametric Design Functionality - Once the initial design concept is sketched, simply selecting the subject dimension, which controls that geometry, and type in a new value, can make any future geometry adjustments to those sketches. The geometry will automatically update, corresponding to the new dimension, as well as any other geometry affected by the dimensional change. This feature allows for blistering fast design changes, as well as development of new parts. Parametric design represents the "critical element" required to achieve rapid customizations, inherent within the short cycle, customer oriented, demand driven "Lean manufacturing" environment.
With manufacturers worldwide moving to "Lean Manufacturing." Short cycle product design, and cross-functional team approaches to product development have become the new competitive weapon. Achieving this requires geometric data to be shared between many different disparate groups. This requires geometric data be clear and understandable. 2D drafting worked well in the past, however, for manufacturers looking to survive and grow in a "Collaborative Global Economy," making the leap from traditional 2D Drafting to 3D Solid modeling must be the center piece of their "Lean" business strategy.
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