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UNITEN. Dr. HABEEB HATTAB HABEEB Office: BN-Block, Level-3, Room-088 Email: hbuni61@yahoo.com Ext. No.: 7292. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional.
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UNITEN Dr. HABEEB HATTAB HABEEB Office: BN-Block, Level-3, Room-088 Email: hbuni61@yahoo.com Ext. No.: 7292 Lecturer: Dr. HABEEB ALANI University TENAGA Nasional University TENAGA Nasional Lecturer: Habeeb Al-Ani
UNITEN University TENAGA National College Of EngineeringMechanical DepartmentAcademic Year – 2008-2009 Lecture Note Lecturer: Dr. HABEEB ALANI University TENAGA Nasional University TENAGA Nasional Lecturer: Habeeb Al-Ani
UNITEN Computer Aided Manufacturing CAM Lecturer: Dr. HABEEB ALANI University TENAGA Nasional University TENAGA Nasional Lecturer: Habeeb Al-Ani
Process Planning Principle activity of manufacturing engineering includes Deciding which process and methods to be used in what sequence Determining tooling requirements Selecting production equipment and systems Estimating cost of production of selected process, tooling, and equipment Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Computer Aided Process Planning (CAPP) CAPP is an automated process planning, can be divided into two main sytems Retrieval Systems Generative Systems Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Retrieval CAPP systems Based on group technology (GT) and part classificationand coding a standard process plan is stored in computer files for each part code number. GT: Similar parts identified and grouped together in order to take advantage of their similarities in design and production. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Generatival CAPP systems Alternative to Retrieval systems. Rather than retrieving and editing an existing plans from a data base, a generative system creates the process plan using systematic procedures that might be applied by a human planner. In fully Generative CAPP system, a process sequence is planned without human assistance and predefined parts. It is a branch of artificial inteligence “Expert Systems”. Computer Programs are capable of solving complex problems that normally requires a human. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Generative CAPP systems (continue) Several ingredients needed Knowledge Base: Technical knowledge of manufacturing and the logic used by a succesfull process planners must be captured and coded into a computer program. Generative CAPP systems use the knowledge base to solve the process planning problems and to create “route sheets”. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Generative CAPP systems (continue) 2. Computer Compatible Part Description: Description contains all the data needed to plan the process sequence. For example Geometric model of the part developed on a CAD system. Group technology code number of part defining its significant features is given. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Generative CAPP systems(continue) Inference Engine: A generative CAPP system requires the capability to apply the planning logic and process knowledge contained in the knowledge base to a given part description. CAPP applies its knowledge base to solve a specific problem of planning the process for a new part. This procedure is called “Inference Engine” Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Benefits of CAPP systems Process rationalization and standardization (logical and consistent) Increased productivity (greater number of process plans to be developed) Reduced lead time Improved legibility Interfacing with other programs (cost estimation, etc..) Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Design for Manufacturing and Assembly (DFM/A) To implement DFM/A, a company mustmake changes in its organizaitonal structureand design principles and guidelines. Organizational changes need to be done to have betterintractionbetweendesignand MFG personnel. Organizational changes must contain : a)Team formed of designer, manufacturing engineers, quality engineers, material engineers.. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
(DFM/A)(cont.) b)Designers must spend some time in manufacturing area. c)A manufacturing engineer should consult the designers. 2) One of the guide lines in designing is to make it as simple as possible, but in design for assembly, additional features are required, such as; to be technically good in manufacturing, is it safe from copying( can competitors learn the secrets of our product by reverse engineering?). Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Benefits of DFM/A Shorter time to bring product to the market Smoother transition into production Fewer components in final product Easier assembly Lower cost of production Higher product quality Greater customer satisfaction Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Design for Quality (DFQ) Traditional quality control has been concerned with detecting the or quality in manufactured products and taking corrective action to eliminate it. The modern view of quality control encompasses a broader scope of activities including robust design and statistical process control. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Design for Quality (DFQ)(continue) Robust Design: Product’s function and performance is not sensitive to the variations in design and manufacturing parameters. It involves the design of both the product and process. Statistical Process Control(SPC): Involving the use of statistical methods to assess and analyze the variations in process. This method includes keeping records of production data and charts. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Design for Life Cycle Factors associated with life cycle 1)Delivery: Transport cost, delivery time, etc.. 2)Installation: Utility requirements. 3)Reliable: Service life, failure rates, etc.. 4)Maintaining: Design modularity, maintenance requirements. 5)Service: Spare parts, field service. 6)Human factors: Complexity of controls, risks, etc.. 7)Upgrading: Compatibility to the future designs. 8)Disposability: Recycling of components, waste hazards, etc.. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Design for Cost In manufacturing our main aim is to reduce the cost of production. Of course we need to make the processes easy and quality high. Choosing the best material and manufacturing processes among all the available materials and processes is a complex decision making. In cost reducing there is two main factors Role of materials Role of manufacturing processes Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Role of Materials Understand the functional requirements of each part, choosing criteria will include Mechanical properties of the material: Strength, toughness, ductility, hardness, etc.. Physical properties of the material: Density, melting point, thermal expansion, etc.. Chemical properties of the material: Oxidation, corrosion, etc.. Shape of the material:Need to select the shape with respect to the design, therefore it requires less additional process. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Role of Materials (continue) Manufacturing properties of the material: Need to select the suitable material for the process that is going to be applied. Material supply: Location of the plant, location of the country, politics in the country affects the availabitiy of the material. Therefore the cost. Material cost: Cost of a raw materialdepends not only on the material itself but also on its shape, size and condition. Also, price of a material decreases as the volume increases.Demand is another aspect in the price of a material. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Role of Materials (continue) Product design: Cost of material is a significant portion of product cost. This cost can be reduced by optimization in design or reducing thickness. But minimization in material thickness may cause problems in manufacturing. Substitution of materials: New products appear continually in the market to substitude the materials in use. The purpose of substitution is to reduce the cost of the material, to improve manufacturing and assembly, to reduce maintenance, etc... Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Role of Manufacturing Processes Proper selection of manufacturing processes and machinery depends on various considerations like: Properties of the work material The shape and the size of the work material Surface finish and dimensional tolerances Quantity of the production Functional requirements Process capabilities. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Manufacturing Cost Material cost Tooling cost Fixed costs Capital costs Direct labor costs Indirect labor costs Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Manufacturing Cost (continue) Fixed costs:Electric, fuel, taxes, rent, insurance type of costs called fixed costs. These costs are not sensitive to the production volume. Capital costs:Investment in land, building, machinery,tooling and equipment. Direct labor costs:Includes all labor, from the time raw materials are first handled to the time when the product is finisihed. This period is called as floor-to-floor time, and the personnel is called productive labor. Indirect labor costs:These costs are refered to as overhead (burden rate) and charged proportionally to all products. The personnel involved in activities such as quality control, repair, maintenance, engineering, research, sales, etc called non-productive labor creates these costs. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Manufacturing Cost and Production Rate Approximate cost division Design 5% Material 50% Direct labor 15% Overhead 30% Of course the direct labor costs changes with respect to the manufacturing volume. High volume type of manufacturing includes dedicated machinery which needs less direct labor. On the other hand small volume productions needs more direct Labor since the machinery used is general purpose type of Machines and needs more human interaction. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Cost Reduction Cost can be reduced by Simplifying part design Allowances of rougher surface finish and broader tolerancing Using less expensive material Investigating the alternative ways of manufacturing(see the figure next slide) Using efficent machinery Since manufacturing adds value to materials by using value analysis methods we can reduce the cost. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Methods of Making a Part • Various methods of making a simple part: • casting or powder metallurgy. • (b) forging or upsetting. • (c) extrusion. • (d) machining. • (e) joining two pieces. Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
Value Analysis Value analysis consists of six phases Information phase: gather data and determine cost Analysis phase:Identify problems and opportunities Creativity phase:Seek ideas to solve problems Evaluation phase: Select ideas and identify costs involved. Implementation phase:Take necessary actions to accomplish the task Review phase: Analyze to see if any adjustment is needed Lecturer: Dr. HABEEB ALANI University TENAGA Nasional
End of presentation THANK YOU Lecturer: Dr. HABEEB ALANI University TENAGA Nasional