SCM 301 Chapter 8: Lean and Six Sigma in the Supply Chain
Cause and Effect Diagrams (Fishbone or Ishikawa diagrams)
Used to aid in brainstorming & isolating the causes of a problem.
Lean Thinking
Includes delivering smaller quantities, more frequently to point of use
Attribute Data
Indicate some attribute such as color & satisfaction, or beauty.
Design Quality
Inherent value of the product in the marketplace. i.e. performance, features, reliability, durability, serviceability, response, aesthetics, and reputation.
Assignable Variations
Have a specific cause (can control)
The DMAIC Improvement Cycle
1. Define 2. Measure 3. Analyze 4. Improve 5. Control
Key elements of Process Management and have emerged as philosophies and practices known as
1. Lean Production (lean manufacturing) 2. Six Sigma
Lean Production (Lean manufacturing)
An operating philosophy of waste reduction & value enhancement & was originally created as Toyota Production System (TPS) by key Toyota executives
Customer's Risk
Buyer accepts a shipment of poor-quality units because the sample falsely provides a positive answer (Type II error).
Variable Data
Continuous (i.e. weight)
ECR
Efficient consumer response - speed & flexibility
Inventory & Setup Time Reduction
Excess inventory is a waste. Reducing inventory levels causes production problems. Once problems are detected, they can be resolved. The end result is a smoother running organization with less inventory investment.
Natural Variations
Expected and random (cannot control)
Lean Production & the Toyota Production System: Key concepts incorporated in TPS are
Muda Kanban Statistical process control (SPC) Poka-Yoke Yokoten
Six Sigma
Near quality perfection. Pioneered by Motorola in 1987. A statistics-based decision-making framework designed to make significant quality improvements in value-added processes.
Attribute Data Control Charts
P Chars: monitor the percent defective in each sample. C Charts: count the number of defects per unit of output.
Keiretsu Relationships
Partnership arrangements
QR
Quick response - speed & flexibility
Lean Supply Chain Relationships
Suppliers & customers work to remove wast, reduce cost, & improve quality & customer service
Check Sheets
To determine frequencies for specific problems.
Conformance Quality
Degree to which the product or service design specifications are met. This is the primary focus of Six Sigma and Lean projects!
Small Batching Scheduling
Drives costs down by reducing purchased, WIP, & finished goods inventories. Makes the firm more flexible to meet customer demand.
Waste (Muda) Reduction
Firms reduce costs & add value by eliminating waste from the productive system. Waste encompasses wait times, inventories, material & people movement, processing steps, variability, any other non-value-adding activity.
Pareto Charts
For presenting data in a organized fashion, indicating process problems from the most to least severe.
JIT
Just in time - continuous reduction of waste
Workforce Commitment
Managers must support lean production by providing subordinates with the skills, tools, time, & other necessary resources to identify problems & implement solutions
Lean Production emphasizes
Reduction waste, continuous improvement, synchronization of material flows within the organization, channel integration (extending partnerships in the supply chain)
Acceptance Sampling
When shipments are received from suppliers, samples are taken and measured against the quality acceptance standard. Shipments is assumed to have the same quality.
Six Major Sources of Variation
1. People 2. Machines 3. Materials 4. Methods 5. Measurements 6. Environment
Producer's Risk
A buyer rejects a shipment of good quality units because the sample quality did not meet standards (type I error).
Lean Layouts
More people & materials when & where needed, ASAP. They are very visual with operations at one processing center able to monitor work at another
Quality at the source
Person who does the work takes responsibility for making sure the output meets specifications.
Manufacturing Cells
Process similar parts or components saving duplication of equipment & labor. Are often U-shaped to facilitate easier operator & material movements.
Defects per Million Opportunities (DMPO)
Six Sigma allows manager to readily describe process performance using a common metric
ISO 9000 and ISO 14000 Families of Management Standards
international Organization for Standardization (ISO) located in Switzerland has > 163 member countries. ISO 9000 & 14000 govern quality and environmental certification standards of production, respectively. ISO standards are voluntary.
The Seven Wastes
1. Overproduction 2. Waiting time 3. Transportation 4. Excess inventory 5. Over processing 6. Excess motion 7. Defects / rework
The 5 S's of Waste Reduction
1. Sort (organize) 2. Set in order (tidiness) 3. Sweep (shine / purity: cleaning) 4. Standardize (cleanliness - simplify processes) 5. Self-discipline (sustain / maintain) Can be employed in any service or manufacturing firm by doing a "waste hunt"
Elements of Lean
1. Waste reduction 2. Lean supply chain relationships 3. Lean layouts 4. Inventory & setup time reduction 5. Small batch scheduling 6. Continuous improvement 7. Workforce empowerment
Statistical Tools of Six Sigma: Statistical Process Control
Allows firms to - 1. visually monitor process performance 2. compare the performance to desired levels or standards 3. take corrective action Fims - 1. gather process performance data 2. create control charts to monitor process variability 3. then collect sample measurements of the process over time and plot on charts
Flow Diagrams
Annotated boxed representing process to show the flow of products or customers.
Process Management
Is the appreciation of knowledge, skills, tools, techniques, and systems to define, visualize, measure, control, report, and improve processes with the goal to meet customer requirements efficiently.
Continuous Improvement
Kaizen, continuous approach to reduce process, delivery, & quality problems, such as machine breakdown problems, setup problems, & internal quality problems
Small production batches are accomplished with the use of
Kanbans. Kanbans generate demand for parts at all stages of production creating a "pull" system.