LEAN Mean Manufacturing—Fab Efficiency at AMD
Is it possible to save millions of dollars in one year by eliminating wasted time and resources across your manufacturing operations? Definitely, says Doug Grose of AMD, who sees “dramatic improvements in efficiency and productivity at AMD through aggressive and consistent process improvement using LEAN methodologies.” Grose, senior VP of Manufacturing, Process Technology Development and Supply Chain at AMD, presented at the Advanced Semiconductor Manufacturing Conference 2008 in Cambridge, Massachusetts on May 5, 2008.
AMD has linked together a LEAN supply chain that emphasizes increasing customer satisfaction, improving service levels, reducing inventory, and reducing days that sales are outstanding. Using Lean concepts, AMD has transformed the “supply chain” to a “value chain” that spans IDMs, suppliers, and clients.
What is LEAN?
First, Grose clarified what LEAN is, and what it isn’t. LEAN is about eliminating wasted time and resources, and about maximizing process velocity and building quality into workplace systems. LEAN is about building a learning culture for continuous improvement. On the other hand, LEAN is not just a methodology to bring a process under statistical control. It is not a cost reduction methodology—although process change may result in cost reduction.
Lean started as “Training within Industry” in the U.S. during World War II. It was introduced to Japan during Post-War rebuilding. Then it was adopted by Toyota in the early 1950s, and developed into the Toyota Production System. The phrase Lean was coined in the 1980’s by James Womak in his book: The Machine that Changed the World.
Fab 30 in Dresden—Pioneering LEAN in Fabs
According to Grose, AMD’s Fab 30 in Dresden was a pioneer in the development and introduction of LEAN principles into fabs. In 2005, LEAN was first implemented with 200 mm in Fab 30. In AMD’s 300 mm Fab 36 for microprocessors, output continues to increase. After aggressively transitioning to 65nm, 45nm ramp is occurring now.
Increasing Complexity in AMD’s World
Grose says that life used to be “relatively simple in AMD’s world.” Design in Texas and California fed the Primary Core, which in turn fed into Fab 30 in Dresden. Then debug PDE/Design/PM took place (often circling back to the fab) with Penang and Singapore taking over before delivering product to the OEMs and into the channels. However, the AMD world is getting increasingly complex (see Figure 1).
LEAN Success Factors and Fab Waste Categories
Success involves putting processes first—as the focal point of attention, and making them measureable with quantified targets for improvement. Grose says that it is key to separate waste and value from the perspective of the customer, and to eliminate waste through structured continuous improvement involving all levels of the organization.
According to Grose, the main categories of “waste-drivers” in a fab are:
1. Overproduction and unsynchronized processes (e.g., content, meetings)
2. Stocks (e.g., data, queues on the critical path, multi-project environment)
3. Waiting (e.g., for capacity, feedback)
4. Transport/Handoffs (e.g., logistics, extensive data)
5. Movement (e.g., remote departments)
6. Over Specification (e.g., not required functionality)
7. Defects (e.g., insufficient quality of components, information)
8. Re-Inventions (e.g., ineffective documentation)
9. Lack of “System Discipline” (e.g., lack of training of associates, thinking of downstream processes.
Grose emphasizes that the concept of “waste and value” is crucial to success, and there are three kinds of work: Work with added value (Work that adds value to the product—and for which the customer is willing to pay), Work with accepted waste (Work that does not add to the product’s value but which may be required under certain circumstances), and Work with unaccepted waste (Activities that are definitely not required to add value to the product).
Real Examples of LEAN Success from the Fab Floor
The presentation included numerous examples with quantifiable data, including:
1. Lean on the Fab Floor: Since February 2005, when LEAN was implemented at the Dresden fabs, Capacity (wafer starts per week) increased 31% and labor productivity (monthly activities per operator) increased 72%. Monthly wafer cost decreased 26% and cycle time per mask layer (days) decreased 23%.
2. New Work Flow Layout Results in 37% Cut in Lead Time: The first “process flow” example involves workflow in a new Bump Test Facility at AMD. To reduce waste workflow, the layout of the new Controlled Collapse Chip Connection (C4) area was designed along the work flow. This dramatically reduced waste in lot movement through C4. According to Grose, lot travel distance was reduced from 925 meters to 363 meters (63% reduction). Lead time variability went from 2.86 days to 0.83 days (71% reduction). Lead time went from 4.21 days to 2.64 days—a 37% decrease.
3. Preventative Maintenance Downtime Reduced: AMD extended the frequency between preventative maintenances and rearranged the maintenance to spread it out evenly over the entire year. Preventative maintenance length was limited to one working shift. In etch, preventative maintenance downtime was reduced by 35%. In thin films, chamber and kit change time was reduced by 60%. As for Cu plating results, preventative maintenance downtime was reduced by 75%— with a gain of about 5% uptime!
4. Supplier Integration into AMD’s Lean Program: AMD worked with Semitool Inc. to focus on overall quality, including the following process improvement goals: delivered parts and tools, equipment reliability, parts delivery performance, project management, on-site service, and business processes.
5. LEAN Principles in the AMD Value Stream: Penang, the first AMD “fully LEAN” facility, realized a 20 percent productivity increase, a reduction in labor (3 less operators), and $55,000 savings per quarter. In Singapore, LEAN principles cut material transportation by 94 percent and lead time by 95 percent. In Suzhou, LEAN improvements included 60 percent less lead time, a 17 percent increase in productivity, and an 88 percent drop in Work-in-Progress (WIP).
6. Back-End Operations: Back-end operations typically incur over 50 percent of costs. Incorporating LEAN techniques into the AMD Singapore facility resulted in: a reduction in cycle time (25%) and production time (47%). Space efficiency increased 25%. Output (per line per week) increased 75,000.
The Bottom Line = Dollars Saved
In 2007, Grose estimates that AMD’s program saved at least $1.1 million in labor, $5.2 million in inventory reduction, $12.0 million in repair and maintenance (cost avoidance), and $37.4 million in Cap-Ex and other savings (cost avoidance, absorbed contract manufacturing) in back-end operations alone.
In summary, Grose remarks that the implementation of LEAN Principles provides long-term, measurable benefits. Those benefits can only be achieved by long-term continuous improvement activities and utilization of the creative potential of all process participants
For more information about Lean, Grose suggests contacting the LEAN Enterprise Institute at http://www.lean.org/ (free to join), or reading Lean Thinking by James Womack and Daniel Jones or The Toyota Way by Jeffrey Liker.
To read a May 2008 IEEE article on "The New Economics of Semiconductor Manufacturing," click here.