Session 01-Introduction to Computer Aided Design and Manufacturing PDF

DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Session 01 Introduction to Computer Aided Design and Manufacturing Contents Introduction 1 1.1 Manufacturing 2 1.3 Production 3 1.4 Product Life Cycle (PLC) 4 1.4 Computers in Manufacturing I...

DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Session 01 Introduction to Computer Aided Design and Manufacturing Contents Introduction 1 1.1 Manufacturing 2 1.3 Production 3 1.4 Product Life Cycle (PLC) 4 1.4 Computers in Manufacturing Industries 6 1.5 The Design Process 9 1.6 Role of Computers in Design 13 1.7 Role of Computers in Manufacturing 14 1.8 Prototype Development 16 1.9 Computer Integrated Manufacturing (CIM) 17 1.10 Definitions 19 Introduction Today’s industries cannot survive worldwide competition unless they introduce new products with better quality (quality, Q), at lower cost (cost, C), and with shorter lead time (delivery, D). Accordingly, they have tried to use the computer’s huge memory capacity, fast processing speed, and user-friendly interactive graphics capabilities to automate and tie together otherwise cumbersome and separate engineering or production tasks, thus reducing the time and cost of product development and production. By tradition, manufacturing has been thought to be a process that turns raw materials into physical products, and the factory, in managing fragmented communications protocols and automation practices, is the structure where manufacturing happens. In recent years, intense international competition has forced companies to seek better manufacturing techniques and 1 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing systems with a higher level of automation to increase productivity gain and improve quality end product. One of the possible solutions is through the effective use of digital computers and their peripherals in the design and manufacture of products. Because of the advancement of hardware and software in digital computers, their use in the design and manufacture of products has greatly reduced the manufacturing cost and constitutes substantial productivity gains in various industries. This application of digital computers in manufacturing has evolved into a new technology commonly known as Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM). Computer-aided design can be described as any design activity that effectively utilizes digital computers to create, retrieve, modify, draft, and store an engineering design; while the Computer-Aided Manufacturing International defines computer- aided manufacturing as the effective utilization of computer technology in the management, control, and operations of the manufacturing facility through either direct or indirect computer interface with the physical and human resources of the company to produce high-quality end products. (IEC) (LEE) 1.1 Manufacturing Manufacturing is concerned with making products and it is the backbone of any industrialized nation. The word manufacture first appeared in English in 1567 and is derived from the Latin word manufactures, means made by hand. In modern context it involves making products from raw material by using various processes, by making use of hand tools, machinery or even computers. (Singh, 2006) A manufactured product may itself be used to make other products, such as a large press, to shape flat sheet metal into automobile bodies, a drill, for producing holes, industrial sawing machines, for making clothing at high rates, and numerous pieces of machinery, to produce an endless variety of individual items, ranging from thin wire for guitars and electric motors to crankshafts and connecting rods for automotive engines. Because a manufactured item typically starts with raw materials, which are then subjected to a sequence of processes to make individual products, it has a certain value. For example, clay has some value as mined, but when it is made into a product such as cookware, pottery, an electrical insulator, or a cutting tool, value is added to the clay. (Kalpakijan) 2 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing 1.2 Production It is the process followed in a plant for converting semi- finished products or raw materials into finished products or raw materials into finished products. The art of converting raw material into finished goods with application of different types of tools, equipments, machine tools, manufacturing set ups and manufacturing processes, is known as production. Generally, there are three basic types of production system that are given as under. 1. Job production 2. Batch production 3. Mass production 4. Continues – flow process (Continues dedicated production of large amount of bulk product such as Oil, Chemicals) Figure 1.1 Types of Manufacturing/ Production Systems Job production comprises of an operator or group of operators to work upon a single job and complete it before proceeding to the next similar or different job. The production requirement in the job production system is extremely low. It requires fixed type of layout for developing same products. Manufacturing of products (less in number say 200 to 800) with variety of similar parts with very little variation in size and shape is called batch production. Whenever the production of batch is over, the same manufacturing facility is used for production of other batch product or items. The batch may be for once or of periodical type or of repeated kinds after some irregular interval. 3 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Whereas mass production involves production of large number of identical products (say more than 50000) that needs line layout type of plant layout which is highly rigid type and involves automation and huge amount of investment in special purpose machines to increase the production. (Singh, 2006) 1.3 Product Life Cycle (PLC) Every product goes through a cycle from birth, followed by an initial growth stage, a relatively stable matured period, and finally into a declining stage that eventually ends in the death of the product as shown schematically in Figure. The life cycle of a new product generally consists of the following four stages: l. Product start-up (Introduction) 2. Rapid growth of the product in the marketplace 3. Product maturity 4. Decline. Figure 1.2 Product Life Cycle 1) Introduction stage: In this stage the product is new, and the customer acceptance is low and hence the sales are low. 2) Growth stage: Knowledge of the product and its capabilities reaches to a g rowing number of customers. 3) Maturity stage: The product is widely acceptable, and sales are now stable, and it grows with the same rate as the economy grows. 4 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing 4) Decline stage: At some point of time the product enters the decline stage. Its sales start decreasing because of a new and a better product has entered the market to fulfill the same customer requirements. Consequently, life-cycle engineering requires that the entire life of a product be considered, beginning with the design stage and on through production, distribution, product use, and, finally, recycling or the disposal of the product. 1.3.1 Product Life Cycle in design and manufacturing To appreciate the scope of CAD/CAM in the operations of a manufacturing firm, it is appropriate to examine the various activities and functions that must be accomplished in the design and manufacture of a product. The product design and development stage begin with a market need and ends with the actual product in the market. With changing market demand, it is important that a product reaches the market within the shortest possible time. The traditional product life cycle consists of two stages as follows: (Srinivas) 1. Design stage 2. Manufacturing Figure 1.3 Typical product life cycle of a component (Design & Manufacturing) 5 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Figure 1.4 Utilization of CAD/CAM in Product life cycle 1.4 Computers in Manufacturing Industries Factors governing increased productivity, more accuracy, greater flexibility of shapes, and reduced manufacturing costs are forcing the manufacturing concerns to use computers in design, manufacturing and other allied functions of industrial activities. With an increase in the need for quality manufacturing along with the factors such as short lead time and short product lives and increasing consumer awareness as regards the quality of the product, it is becoming increasingly important for the manufacturers to initiate steps to achieve all these. The developments in microelectronics in the recent past have made higher computational ability available at a low cost. Therefore, it becomes imperative that manufacturing takes advantage of the availability of low cost and also using yet more powerful computers. Computers have been in use in manufacturing industries since 1960. Initially they were in use only in supportive functions such as inventory control purchase accounting, etc. (Singh, 2006) Today, computers are not only used in design and manufacturing, but they play also an important role in all manufacturing related activities such as business or financial management, factory level production management, Computer Integrated Manufacturing (CIM) Technologies, CAD, feature and solid modelling, and CAM, manufacturing information, manufacturing system. The important sub-activities of industrial environment have been identified to support with the use of computer in the manufacturing industries. These are given as under: 6 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing 1. Business or Financial Management 1. Costing (CAC) 2. Sales and Marketing 3. Purchase Order Control 4. Vendors 5. Subcontracting 6. Personnel. 2. Factory Level Production management 1. Planning 2. Production Management (CAPM) 3. Manufacturing production scheduling (MPS) 4. Material requirement planning (MRP) 5. Just in time (JIT) 6. Bill of Materials 7. Capacity Planning 8. Inventory Control. 3. Computer Integrated Manufacturing (CIM) Technologies 1. Computer Networks 2. System Design and Analysis 3. Distributed Processing 4. Database Management Manufacturing 5. Modelling and Simulation 6. Expert Systems 7. Quality Engineering. (CAQA, CAQM) 4. Computer Aided Design (CAD) 1. Variational and Parametric 2. Modelling 3. Computer Graphics 4. Graphic Standards 7 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing 5. Inter-graphics exchange specification (IGES) 6. Data exchange file (DXF) 7. Manufacturing Robot Programming 8. Design Analyses Tools 9. Programming 10. Finite element modelling (FEM) 11. Finite element analysis (FEA) 12. Simulation 13. Mechanisms 14. Test and Analysis 15. Design Tools Mechanical 16. Hydraulic, Electronics, etc. 5. Computer Aided Manufacturing (CAM) This involves activities related to manufacturing information and manufacturing systems which are given as under: Manufacturing Information 1. Generation 2. Process Planning / Control (CAPP/ CAPPC) 3. Production Planning 4. Computer numerical control (CNC) part Programming 5. Robot Programming 6. Coordinate measuring machine (CMM) Programming. 6. Manufacturing System 1. Production Activity 2. Machining 3. Assembly 4. Material Handling (CAPM) 5. Storage 6. Production Control (CAPC) 7. Loading 8. Scheduling 8 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing 9. Balancing 10. Capacity Planning 11. Quality Control. 12. Automation 1.5 The Design Process The Design Process is the most important to understand computer aided design effectively. Thus, one should first understand the design process. The design process is an iterative process which checks the suitability of the design again and again. The design process explained here is described by shigley. Figure 1.5 The General Design process (1) Recognition of Need: Recognition of need involves the realization by someone that a problem exists for which some feasible solution is to be found. This might be the identification of some defect in a current machine design activity by an engineer or the perception of a new product marketing opportunity by a salesman. 9 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing (2) Definition of Problem: Definition of problem involves a through specification of the item to be designed. This specification will generally include functional and physical characteristics, cost, quality, performance, etc. (3) Synthesis: During the synthesis phase of the design process various preliminary ideas are developed through research of similar product or design in use. (4) Analysis and Optimization: The resulting preliminary design is then subjected to appropriate analysis to determine their suitability for the specified design constraint. If this design fails to satisfy the constraints, they are redesigned or modified on the basis of the feedback from the analysis. This iterative process is repeated until the proposed design meets the specification or until the designer is convinced that the design is not feasible. (5) Evaluation: The assessment or evaluation of the design against the specification established during the problem definition phase is then carried out. This often requires the fabrication and testing of a prototype model to evaluate operating performance quality, reliability, etc. (6) Presentation: The final phase of design process is the presentation of the design. This include the documentation of the design through drawing, material specification, assembly lists and so on. Traditionally, design and manufacturing activities have taken place sequentially, as shown in Figure l.5 (Shigley). This methodology may, at first, appear to be straightforward and logical; in practice, however, it is wasteful of resources and time. If need any changes later (Ex: Material) component will likewise necessitate a repeat analysis. Such iterations obviously waste both time and the resources of a company. Consequently, life-cycle engineering requires that the entire life of a product be considered, beginning with the design stage and on through production, distribution, product use, and, finally, recycling or the disposal of the product. 10 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Any product development is time-consuming, and the technology involved to create modern- day products are very complex. Companies can no longer rely on a few engineers to design, develop, and then launch them. The industrial revolution and subsequent continuous technological advancements in many areas have forced people to specialise in a field, which has made companies hire specialised employees. Modern-day new product development is a multi-disciplinary process and relies on functional teams such as, industrial designers, product designers (mechanical, electrical and software engineers), manufacturing, marketing personnel, etc., to get the product to market. 1.5.1 Sequential Engineering (SE) Traditional sequential engineering is the term used to describe linear product development processes, where design and development steps are carried out one after another focusing on one field of expertise at a time. During the industrial revolution, this forced companies to hire specialised people and departments due to products getting more complex. This in turn, paved way to “over the wall” mentality where each team member or department only focused on their tasks and passed the completed work onto the next (Figure 1.4). Figure 1.6 Sequential engineering In sequential engineering product development, costs increase slowly as the activities are sequentially executed by the departments as they get involved in the process. But, at the design- manufacturing phase costs increase rapidly due to change requests & iteration loops where there is back and forth change management process. 1.5.2 Concurrent Engineering (CE) 11 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Concurrent engineering is an approach developed in the 1980s to eliminate some of the issues with the ‘over the wall’ method. There are many advantages to concurrent engineering where different departments work on the different stages of engineering product development simultaneously while designing and developing new engineering products. (design) Figure 1.7 Comparison of Sequential and Concurrent Engineering In concurrent engineering, the design and manufacture of products are integrated with a view toward optimizing all elements involved in the life cycle of the product. In concurrent engineering product development, costs increase rapidly at the beginning of the development due to a larger team getting involved and intensive activities. However, as the product development progresses into the manufacturing and production it gets quicker and costs decrease due to fewer issues to sort and shorter iterative loops. 12 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Figure 1.8 Design changes vs Development time 1.6 Role of Computers in Design Typically, product design first requires the preparation of analytical and physical models of the product for the purposes of visualization and engineering analysis. Although the need for such models depends on product complexity, constructing and studying these models have become highly simplified through the use of computer-aided design (CAD) and computer-aided engineering (CAE) techniques. CAD systems are capable of rapid and complete analyses of designs, whether it be a simple shelf bracket or a shaft in large and complex structures. (Kalpakijan) In general, a Computer Aided Design (CAD) package has three components: a) Design, b) Analysis, and c) Visualization, as shown in the sketch. A brief description of these components follows. a) Design: Design refers to geometric modeling, i.e., 2-D and 3-D modeling, including, drafting, part creation, creation of drawings with various views of the part, assemblies of the parts, etc. b) Analysis: Analysis refers to finite element analysis, optimization, and other number crunching engineering analyses. In general, a geometric model is first created and then the model is analyzed for loads, stresses, moment of inertia, and volume, etc. c) Visualization: Visualization refers to computer graphics, which includes: rendering a model, creation of pie charts, contour plots, shading a model, sizing, animation, etc. 13 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Figure 1.9 Components of Computer Aided Design 1.7 Role of Computers in Manufacturing Computers involves all phases of manufacturing, by utilizing and processing the large amount of information on materials and processes gathered and stored in the organization’s database. The role of computers in manufacturing may be broadly classified into two groups: 1. Computer control and monitoring. These are the direct applications in which the computer is connected directly to the manufacturing process for the purpose of monitoring or controlling the process. 2. Manufacturing support applications. These are the indirect applications in which the computer is used in support of the production operations in the plant, but there is no direct interface between the computer and the manufacturing process. Figure 1.10 Computer monitoring versus computer control Computer monitoring and control can be separated into monitoring applications and control applications. Computer process monitoring involves a direct computer interface with the 14 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing manufacturing process for the purpose of observing the process and associated equipment and collecting data from the process. The computer is not used to control the operation directly. The control of the process remains in the hands of human operators, who may be guided by the information compiled by the computer. Computer process control goes one step further than monitoring by not only observing the process but also controlling it based on the observations. With computer monitoring the flow of data between the process and the computer is in one direction only, from the process to the computer. In control, the computer interface allows for a two-way flow of data. Signals are transmitted from the process to the computer, just as in the case of computer monitoring. In addition, the computer issues command signals directly to the manufacturing process based on control algorithms contained in its software. The second category, in addition to the applications involving a direct computer-process interface are all the support functions that computers can provide for the successful completion of manufacturing operations. In these applications, the computer is not linked directly to the manufacturing process. Instead, the computer is used "off-line" to provide plans, schedules, forecasts, instructions, and information by which the firm's production resources can be managed more effectively. The types of support that can be envisaged are the following: Computer Aided Design (CAD). The use of computer methods to develop geometric model of the product. Computer Aided Design and Drafting (CADD). Combining the CAD functions with drafting to generate production drawings. Computer Aided Engineering (CAE). The use of computer methods to support basic error checking, Analysis, Optimisation, Manufacturability, etc. of a product design. Numerical control part programming by computers. Control programs are prepared for automated machine tools. Computer-automated process planning (CAPP). The computer prepares a listing of the operation sequence required to process a particular product or component. Computer-generate work standards. The computer determines the time standard for a particular production operation. 15 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing Production scheduling. The computer determines an appropriate schedule for meeting production requirements. Material requirements planning (MRP). The computer is used to determine when to order raw materials and purchased components and how many should be ordered to achieve the production schedule. Shop floor control. In this CAM application, data are collected from the factory to determine progress of the various production shop orders. Computer Aided quality Assurance (CAQ). The use of computers and computer- controlled equipment for assessing the inspection methods and developing the quality control and assurance function. Computers greatly assist in organizing the information developed and performing such tasks as programming for numerical control machines and for robots for material-handling and assembly operations, designing tools, dies, molds, fixtures, and work-holding devices, and maintaining quality control. On the basis of the models developed and analyzed in detail, product designers then finalize the geometric features of each of the product’s components, including specifying their dimensional tolerances and surface-finish characteristics. Because all components, regardless of their size, eventually have to be assembled into the final product, dimensional tolerances are a major consideration in manufacturing. Indeed, dimensional tolerances are equally important for small products as well as for car bodies or airplanes. The models developed also allow the specification of the mechanical and physical properties required, which in turn affect the selection of materials. 1.8 Prototype Development 1.8.1 Prototypes A prototype is a physical model of an individual component or product. The prototypes developed are carefully reviewed for possible modifications to the original design, materials, or production methods. An important and continuously evolving technology is rapid prototyping. Using CAD/CAM and various specialized technologies, designers can now make prototypes rapidly and at low cost, from metallic or nonmetallic materials such as plastics and ceramics. Prototyping new components by means of traditional methods (such as casting, forming, and machining) could 16 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing cost an automotive company hundreds of millions of dollars a year, with some components requiring a year or more to complete. Rapid prototyping can significantly reduce costs and the associated product-development times. Rapid-prototyping techniques are now advanced to such a level that they also can be used for low-volume (in batches typically of fewer than 100 parts) economical production of a variety of actual and functional parts to be assembled into products. 1.8.2 Virtual Prototyping Virtual prototyping is a software-based method that uses advanced graphics and virtual-reality environments to allow designers to view and examine a part in detail. This technology, also known as simulation-based design, uses CAD packages to render a part such that, in a 3-D interactive virtual environment, designers can observe and evaluate the part as it is being drawn and developed. Virtual prototyping has been gaining importance, especially because of the availability of low-cost computers and simulation and analysis tools. 1.9 Computer Integrated Manufacturing (CIM) Computer Integrated Manufacturing (CIM) system is primarily concerned with the integration and management of the total manufacturing process. It is a system that recognise and supplies computer services to each phase of the manufacturing cycle independently, while at the same time maintaining a database that serves a single source of data for all company activities and applications. The term Computer-Integrated Manufacturing (CIM) is often used interchangeably with Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM). Although the terms are closely related, CIM is interpreted to possess a slightly broader meaning and in scope than CAD/CAM. Computer-Integrated Manufacturing (CIM) includes all the engineering function of CAD/CAM, but also includes the business function of applies technology for all of the operational function and information processing functions in manufacturing from order receipt, through design and production to product shipment and service and field support after sales. Computer Integrated Manufacturing (CIM) is a term used to describe a facility for manufacturing a variety of products using computers to initiate, control and monitor the activities. CIM = CAD/CAM Functions + Business functions 17 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing The scope of CIM and computerized element of the CIM system is as shown in (Fig. 1.8 and 1.9) The CIM concept is that all of the films operations related to production function are incorporated in an integrated computer system to assist argument and or automate the operations. It touches all the activities that support manufacturing, with the output of the activity serving as the input to the next activity through the chains of events that starts with the sales order and end with shipment of product. Customer orders are initially entered by the company’s sales force into computerised order entry systems. The orders contain the specifications describing the products. The specification serves as the input to the product design department. One of the most daunting challenges in Computer Aided design (CAD) and Computer Aided Manufacturing (CAM). Figure 1.11 Scope of CIM Figure 1.12 Computerized elements of a CIM system 18 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing It consists of a lot of sub-systems that are integrated into a whole. The subsystems are - Business planning and support, - Product design; - Manufacturing process planning, - Process control; - Shop floor monitoring systems; and - Process automation. The subsystems are designed, developed, and applied in such a manner that the output of one subsystem serves as the input of another subsystem. 1.9.1 The Scope of CIM The Computer-Integrated Manufacturing (CIM) incorporate many of the individual CAD/CAM technologies and concepts which is the basic concepts. The technologies are; (i) Computer-Aided Design (CAD) (ii) Computer-Aided Manufacturing (CAM)- Planning; (iii) Computer-Aided Manufacturing (CAM)- Control; (iv) Computerized Business System 1.10 Definitions Computer-aided engineering (CAE) is the broad usage of computer software to aid in engineering analysis tasks. It includes finite element analysis (FEA), computational fluid dynamics (CFD), multibody dynamics (MBD), durability and optimization. It is included with computer-aided design (CAD) and computer-aided manufacturing (CAM) Computer-aided design (CAD) is the use of computers (or workstations) to aid in the creation, modification, analysis, or optimization of a design. CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through 19 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy DMX5212 – Unit I Session 01: Introduction to Computer Aided Design and Manufacturing documentation, and to create a database for manufacturing. CAD output is often in the form of electronic files for print, machining, or other manufacturing operations Computer-aided manufacturing (CAM) is the use of software to control machine tools and related ones in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most common. CAM may also refer to the use of a computer to assist in all operations of a manufacturing plant, including planning, management, transportation and storage. Its primary purpose is to create a faster production process and components and tooling with more precise dimensions and material consistency, which in some cases, uses only the required amount of raw material (thus minimizing waste), while simultaneously reducing energy consumption. Integrated CAD/CAM is a term which means Computer-Aided Design and Computer-Aided Manufacturing. CAD/CAM technology is moving in the direction of greater integration of design and manufacturing, two activities which have traditionally been treated as distinct and separate function in production form. Computer-aided design and manufacturing systems are commonly referred to as CAD/CAM. Ultimately, CAD/CAM will provide the technology base for the computer-integrated factory of the future. 20 Copyright © 2019, The Open University of Sri Lanka (OUSL) Experimental Copy