Management Guide: Six Sigma – DFSS Methodology

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Six Sigma

Six Sigma DMAIC

Six Sigma DFSS

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iSixSigma

Contents

Design for Six Sigma - IDOV Methodology

Identify Phase

Design Phase

Optimise Phase

Validate Phase

Design for Six Sigma - IDOV Methodology

Design for Six Sigma (DFSS) can be accomplished using any one of many methodologies. IDOV is one popular methodology for designing products and services to meet six sigma standards.

IDOV is a four-phase process that consists of Identify, Design, Optimise and Validate. These four phases parallel the four phases of the traditional Six Sigma improvement methodology, MAIC - Measure, Analyse, Improve and Control. The details of each phase can be seen below.

Identify Phase

The Identify phase begins the process with a formal tie of design to Voice of the Customer (VOC). This phase involves developing a team and team charter, gathering VOC, performing competitive analysis, and developing CTQs.

Crucial Steps:

• Identify customer and product requirements
• Establish the business case
• Identify technical requirements (CTQ variables and specification limits)
• Roles and responsibilities
• Milestones

Key Tools:

• QFD (Quality Function Deployment)
• FMEA (Failure Means and Effects Analysis)
• SIPOC (Supplier, Input, Product, Output, Customer product map)
• IPDS (Integrated Product Delivery System)
• Target Costing
• Benchmarking

Design Phase

The Design phase emphasises CTQs and consists of identifying functional requirements, developing alternative concepts, evaluating alternatives and selecting a best-fit concept, deploying CTQs and predicting sigma capability.

Crucial Steps:

• Formulate concept design
• Identify potential risks using FMEA
• For each technical requirement, identify design parameters (CTQs) using engineering analysis such as simulation
• Raw materials and procurement plan
• Manufacturing plan
• Use DOE (design of experiments) and other analysis tools to determine CTQs and their influence on the technical requirements (transfer functions)

Key Tools:

• Smart simple design
• Risk assessment
• FMEA
• Engineering analysis
• Materials selection software
• Simulation
• DOE (Design of Experiments)
• Systems engineering
• Analysis tools

Optimise Phase

The Optimise phase requires use of process capability information and a statistical approach to tolerancing. Developing detailed design elements, predicting performance, and optimising design, take place within this phase.

Crucial Steps:

• Assess process capabilities to achieve critical design parameters and meet CTQ limits
• Optimize design to minimize sensitivity of CTQs to process parameters
• Design for robust performance and reliability
• Error proofing
• Establish statistical tolerancing
• Optimise sigma and cost
• Commission and startup

Key Tools:

• Manufacturing database and flowback tools
• Design for manufacturability
• Process capability models
• Robust design
• Monte Carlo Methods
• Tolerancing
• Six Sigma tools

Validate Phase

The Validate phase consists of testing and validating the design. As increased testing using formal tools occurs, feedback of requirements should be shared with manufacturing and sourcing, and future manufacturing and design improvements should be noted.

Crucial Steps:

• Prototype test and validation
• Assess performance, failure modes, reliability, and risks
• Design iteration
• Final phase review

Key Tools:

·        Accelerated testing

• Reliability engineering
• FMEA
• Disciplined New Product Introduction (NPI)