Manufacturing Processes for Engineering Materials (5th Edition in SI Units) Chapter 16: Product Design and Manufacturing in a Global Competitive Environment 1

Index Quality Material Manufacturing Cost

Product Design and Robust Design Software helps designers develop products which reduced assembly and manufacture time. Some product design considerations: Simplified product design Environmental considerations Alternative designs Unnecessary features are eliminated Modular design

Product design and quantity of materials High production rates and reduced labour made automation and computer integration possible. Reductions in materials require selection of materials with high strength-to-weight ratios. Robustness and robust design - Robustness is defined as a design that functions within acceptable parameters. Yet its difficult or impossible to control.

Quality as a manufacturing goal Product quality includes well-defined technical considerations and human opinion. High product quality includes: High reliability Performs, functions well and safely Good appearance Inexpensive Upgradeable Robustness

Quality as a manufacturing goal Concept of continuous improvement in quality means that there should be never-ending improvement. Concurrent engineering design is to select specific materials for components for a particular product. Concept of return on quality (ROQ) is: Making sure quality is an investment. Limit on how resources should be explanded. Having quality improvement.

Total quality management Total quality management (TQM) is a system that emphasizes that quality must be designed and built into a product. Both management and employees make an effort to manufacture high-quality products without any defects. Quality circle Concept consists of regular meetings. Worker involvement, responsibility, creativity and team effort are emphasized.

Deming methods

Taguchi methods High quality and low costs are achieved by engineering and statistical methods. Loss of quality will result in: customer dissatisfaction costs are incurred marketplace is diminished loses its company share in the market

Taguchi methods Taguchi methods of quality engineering emphasizes the importance of: Enhancing cross-functional team interaction Implementing experimental design Taguchi loss function σ = standard deviation of parts Y = mean value from manufacturing LSL = lower specification limitation T = target value from design k = constant

Example 16.1 Production of polymer tubing High-quality polymer tubes are being produced for medical applications, where the target wall thickness is 2.6 mm, with an upper specification limit of 3.2 mm and a lower specification limit of 2.0 mm (2.6±0.6mm). If the units are defective, they are replaced at a shipping-included cost of $10.00. The current process produces parts with a mean of 2.6 mm and a standard deviation of 0.2 mm. The current volume is 10,000 pieces of tube per month. An improvement is being considered for the extruder heating system. This improvement will cut the variation in half, but it will cost $50,000. Determine the Taguchi loss function and the payback period for the original production process and incorporating the process improvement.

Example 16.1 Production of polymer tubing Solution The quantity k is given by The loss cost is then After improvement, The savings are The payback period for the investment is

The ISO and QS Standards Customers always demand high-quality products and services at low prices. The ISO 9000 standard Quality Management and Quality Assurance Standards is a generic series of quality-system management standards. Companies which fail to meet the requirements of the standard will not be registered.

Life-Cycle Engineering and Sustainable Manufacturing Product life cycle is concerned with environmental factors, design, optimization and technical considerations of the product. Cradle-to-grave Consecutive and interlinked stages of a product or service system. Sustainable manufacturing The need for conserving these resources through maintenance and reuse.

General properties of materials Mechanical properties of materials include strength, toughness, ductility, hardness and resistance to fatigue, creep and impact. Physical properties include density, melting point, specific heat, thermal and electrical conductivity, thermal expansion and magnetic properties. The chemical properties are oxidation and corrosion.

Shapes of commercially available materials Materials are available in various forms.

Manufacturing characteristics of materials Manufacturing characteristics include castability, workability, formability, machinability, grindability, weldability and hardenability through heat treatment. Quality of a raw material influences its manufacturing characteristics.

Substitution of Materials in Products Product improvements result from: substitution of materials implement new designs, technologies or improved processing techniques better control of processing parameters increased automation

Capabilities of Manufacturing Processes Casting and injection molding can produce complex shapes. Forgings have higher toughness.

Capabilities of Manufacturing Processes Dimensional tolerances and surface finishing Important for functioning of parts, machines, and instruments and assembly operations.

Capabilities of Manufacturing Processes Production quantity or volume Manufacturing discipline is to determine the optimum production quantity. Production rate Production rate is the number of pieces that can be produced per unit of time. Lead time Lead time is the length of time between receipt of order and delivery of product to customer.

Selection of Manufacturing Processes Some considerations are: Properties of the material Geometric features Dimensional-tolerance and surface-finish requirements Functional requirements of the part Production quantity required Costs

Manufacturing Costs and Cost Reduction The total cost of a product consists material, tooling, fixed, variable, direct and indirect labour costs. Costing has the following considerations: quality improvements and inventory reduction life-cycle costs machine usage purchasing cost financial risks

Manufacturing Costs and Cost Reduction Major cost factors are: Material costs Tooling costs Fixed costs Capital costs Labour costs

Cost reduction Cost reduction requires assessment of costs that incurred and interrelated. An approximate breakdown of costs is Cost reductions can be achieved by: simplifying product design reducing the amount of materials investigating alternative methods using more efficient equipments