Product Lifecycle Management Cost of Quality Pasi Kaipainen, Mika Huhta

Cost of Quality Management is an approach to reducing the Cost of Quality (COQ), the sum of all costs incurred throughout the product lifecycle due to poor quality

Cost of Quality Management COQ is made up of 4 types of quality costs: 1. internal failure costs 2. external failure costs 3. appraisal costs 4. prevention costs

Internal failure costs Failures such as rework, scrap and poor design that customer does not see

External failure costs Failures which occur after the product has been delivered to the customer. Includes warranty claims, product liability claims and field returns

Appraisal costs Costs coming from measuring quality and maintaining conformance by such activities as inspection, testing, process monitoring and equipment calibration

Prevention costs Costs coming from reducing the failure and appraisal costs and to achieve first-time quality. E.g. education, training and supplier certification

Six Sigma Six Sigma is a set of practices originally developed by Motorola to systematically improve processes by eliminating defects Six Sigma has two key methodologies: DMAIC (Define-Measure-Analyze-Improve-Control) DMADV (Define-Measure-Analyze-Design-Verify) DMAIC is used to improve an existing business process, and DMADV is used to create new product or process designs for predictable, defect-free performance.

Six Sigma DMADV has several variations (DMEDI, DMADOV and so on …)

Six Sigma-DMAIC Define the process improvement goals that are consistent with customer demands and enterprise strategy. Measure the current process and collect relevant data for future comparison. Analyze to verify relationship and causality of factors. Determine what the relationship is, and attempt to ensure that all factors have been considered. Improve or optimize the process based upon the analysis using techniques like Design of Experiments. Control to ensure that any variances are corrected before they result in defects. Set up pilot runs to establish process capability, transition to production and thereafter continuously measure the process and institute control mechanisms.

Six Sigma-DMADV Define the goals of the design activity that are consistent with customer demands and enterprise strategy. Measure and identify CTQs (critical to qualities), product capabilities, production process capability, and risk assessments. Analyze to develop and design alternatives, create high-level design and evaluate design capability to select the best design. Design details, optimize the design, and plan for design verification. This phase may require simulations. Verify the design, set up pilot runs, implement production process and handover to process owners.

DMAIC cycle

Sigma  The value of the process standard deviation for a given characteristic. Sigma is used to quantify the spread (around a mean) of some process or product characteristic. LSLUSL

Sigma % of the data falls within  6 sigmas from the mean. 66 68.26% 99.73% %

DFSS DFSS:Design For Six Sigma Six sigma tools were initially deployed for the improvement of existing manufacturing or service processes. When new designs were introduced similar Six Sigma solutions were found to be deployed to similar problems again and again.  six sigma problem-solving techniques needed to be incorporated into the design process.

DFSS

DFSS-Definition

Initiate Define and quantify customer requirements. Examine the project fit with business operating and strategic plan. Perform a business and technical risk assessment. Perform a marketing and competitive assessment. Perform a financial assessment —sensitivity analysis. Create a cross-functional team. Determine the timeline.

Design Develop transfer functions. Perform a tolerance analysis. Design for manufacturability/ reliability. Pilot and prototype. Perform an intellectual property review. Perform a risk analysis. Perform a cost/investment review. Review the timeline. Develop a part/raw material procurement plan.

Execute Procure needed equipment and software. Set up manufacturing for production. Execute a commercialization plan. Start up production. Initiate a control plan. Demonstrate short-term manufacturing capability. Verify the short-term risk

Sustain Maintain the control plan. Implement the quality management system. Review actual vs. estimated results. Use MAIC projects as needed to close gaps. Demonstrate long-term performance capability. Close the project.

Process Control C p (and C pk ) is the short-term capability index It is the potential, inherent process capability, or the best the process could ever hope to perform in short-term P p (and P pk ) is the long-term performance index It is also called Process Performance It is the actual, long-term performance of the process in real life

Process Control

Process Capability example PPAP (Production Part Approval Process, Automotive Industry Action Group (AIAG), 1995 states:

PLM and Six Sigma Combine PLM and Six Sigma initiatives together could help to reach targets more effectively since business investments are quite similar for both PLM and Six Sigma.

PLM and Six Sigma