Design/Manufacturing Interface/Production Planning Control MSE508/L Week 12 W, 04/09/08

Agenda Design Manufacturing Interface –TQM (Total Quality Management) or Total Quality –Taguchi Production Planning Control –MRP II –JIT

Design/Manufacturing Interface TQM (Total Quality Management) = The contribution of all parts in an organization to quality A management philosophy A policy of continuous improvement Everybody in an organization should be concerned with assuring the quality of their work, and take continual steps to improve this quality

Design/Manufacturing Interface (Ctnd.) Brown states success comes from the right balance between culture, structure, and organization. Culture: The combination of company values and management style, and the employees reaction to these values Structure: The formal reporting relationships within the organization between departments

Design/Manufacturing Interface (Ctnd.) TQM key principles identified by Lucas Engineering and Systems: Adopt a policy for continuous improvement and innovation in all areas, especially training Reduce the number of suppliers, and involve them in a policy of continuous improvement Provide on-line techniques for problem identification and solution; i.e., extensive use of statistical methods Make use of multi-disciplinary teams in an open, innovative environment; i.e. avoid over-bureaucratic work standards

Design/Manufacturing Interface (Ctnd.) TQM techniques: QDF – Quality Function Deployment DFM – Design For Manufacture Taguchi Method SPC – Statistical Process Control Poka Yoke Process Capability Studies Validation Testing Problem-Solving Techniques CAD/CAM Principles. Practice and Manufacturing, 2 nd Edition by Chris Mahon, and Jimmie Browne, Addison Wesley Limited, 1998, pp

Design/Manufacturing Interface (Ctnd.) How to Measure Quality Traditionally, quality is viewed as a step function as shown by the heavy line graph in the figure 1. A product is either good or bad. This view assumes a product is uniformly good between the specifications (LS the lower specification and US the upper specification). The vertical axis represents the degree of displeasure the customer has with the product's performance. Curves A and B represent the frequencies of performance of two designs during a certain time period. B has a higher fraction of "bad" performance and therefore is less desirable than A.

Design/Manufacturing Interface (Ctnd.) A different method of measuring quality is central to Taguchi's approach to design. Loss function measures quality. The loss function establishes a financial measure of the user dissatisfaction with a product's performance as it deviates from a target value. Thus, both average performance and variation are critical measures of quality. Selecting a product design or a manufacturing process that is insensitive to uncontrolled sources of variation improves quality.

Design/Manufacturing Interface (Ctnd.) Taguchi believes that the customer becomes increasingly dissatisfied as performance departs farther away from the target. He suggests a quadratic curve to represent a customer's dissatisfaction with a product's performance. The quadratic curve is the first term when the first derivative of a Taylor Series expansion about the target is set equal to zero. The curve is centered on the target value, which provides the best performance in the eyes of the customer. Identifying the best value is not an easy task. Targets are sometimes the designer's best guess. Taguchi's loss function

Design/Manufacturing Interface (Ctnd.) Taguchi Method Parameters: Dr. Taguchi calls these uncontrolled sources of variation noise factors. This term comes from early applications of his methods in the communications industry. Noise: Variations in design parameters and in the external environment Outer Noise: Variations in operating environment such as in temperature and humidity, materials being processed, fuel qualities, and human factors Inner Noise: Comprises deterioration in parts and materials from wear, corrosion, damage, etc. Between-Product Noise: Comprises material and manufacturing process variations Goals is to design in such a way as to minimize noise in the final product CAD/CAM Principles. Practice and Manufacturing, 2 nd Edition by Chris Mahon, and Jimmie Browne, Addison Wesley Limited, 1998, pp

Production Planning and Control Two styles of MRP (Materials requirement planning): –Regenerative: Starts with the Master Production Schedule and totally regenerates the whole plan Complete re-analysis of every item in Master All numbers are recalculated Performed weekly or monthly due to the time involved –Net Change: Updates to the plan continually occur, while the system updates as needed Changes in the plan are made and a partial explosion of the BOM’s are made Updates occur immediately on-line or nightly

Production Planning and Control MRP Data Requirements: –MPS (Master Production Schedule) –BOM (Bill of Materials) for each MPS –Inventory Status for each part in the BOM –Lead Time must be available for each part in the BOM MRP Database Information Requirements: –Master Parts information –Full Inventory –BOM –Manufacturing Process for the associated item –Work Centre –Tooling Information

Production Planning and Control MRP II (Manufacturing Resource Planning): –An extension of the MRP System Transaction processing software Decision support RCCP (Rough-Cut Capacity Planning) CRP (Capacity Requirements Planning) Shop floor control CAD/CAM Principles. Practice and Manufacturing, 2 nd Edition by Chris Mahon, and Jimmie Browne, Addison Wesley Limited, 1998, pp

Production Planning and Control JIT (Just in Time) –Involves a continuous commitment to the pursuit of excellence in all phases of manufacturing systems design and operation –JIT seeks to achieve: ZERO Defects ZERO Inventories ZERO Handling ZERO Breakdowns ZERO LEAD Time Lot size of ONE

Production Planning and Control JIT Key Elements: –An intelligent match of the product design with market demand –Definition of product families, and systems that flow –Establish relationships with suppliers for JIT delivery This approach to manufacturing does not restrict attention to the internals of the factory –Looks to find vendors close to the manufacturing plant –Smaller lot size with more frequent deliveries –Sharing database information CAD/CAM Principles. Practice and Manufacturing, 2 nd Edition by Chris Mahon, and Jimmie Browne, Addison Wesley Limited, 1998, pp