General Cable de Latinoamerica S.A. de C.V. Tetla, Tlaxcala, Mexico
Employees: 301, union
Total square footage: 1,152,707
Primary products: Telecommunications exchange cable and service wire
Achievements: Named Best Plant of the Year in North America (an internal award among General Cable Corp. facilities) in 2001, 2004 and 2005; improved productivity (annual sales per employee) by 103% in past three years
Root cause: volcano. Not a likely source of problems in most manufacturing plants certainly, but plausible at General Cable de Latinoamerica S.A. de C.V. The telecommunications wire and cable manufacturer is located in Tetla, Tlaxcala, a high-altitude region of Mexico landscaped with volcanoes.
|See the other winners of IW's 2006 Best Plants award and find out how they made the top ten.|
In fact, Hector Arronte Vicario, quality assurance manager, determined during the course of a project to earn his Six Sigma black belt certification that corrosion of certain aluminum doors could be traced to two water sources -- one being the local water supply, which contains sulphur from nearby volcanoes. The sulphur, Arronte discovered, reacted with copper dust at the plant and provoked the corrosion. Given that the doors cost $28,000 each, Arronte says, finding and resolving the problem offers an obvious opportunity for savings.
Today, Six Sigma and lean manufacturing provide the foundation of General Cable Tetla's drive for manufacturing excellence. Five employees are certified Six Sigma black belts and 26 are green belts. And while some manufacturing literature suggests that lean and process industries aren't an easy fit, the Tetla plant says that lean, in combination with a strong focus on process variation reduction, has helped it achieve performances that include a first-pass yield of 99.97% across all finished products.
Where is lean at work? All over, but examples include comprehensive deployment of visual management systems, as well as a pull system on the shop floor in the service wire product group. (Service wire connects a communications network to a subscriber's location. Its basic configuration is an insulated copper conductor.) Customer orders there are translated into color-coded kanban cards that identify product type, quantity and package configuration for a value stream.
|Martin Luna moves a reel to a kanban rack in preparation for the next process.|
To control the production sequence, heijunka (or leveling) boards have been developed to schedule and maintain balanced production progress. The leveling boards, which contain multiple kanban card slots for each day of the week, are placed at the bottleneck process. Upstream from the bottleneck process, kanban signals trigger machine operators to start and stop the preceding process.
And rather than warehousing finished goods, product in this area is loaded directly onto trucks for customer delivery.
"Over the last several years we have been walking and living the lean culture," Arronte says.
Indeed, the lean focus extends beyond the factory floor. For instance, nearly 85% of the plant's incoming purchased materials no longer require incoming inspection, freeing up resources for other activities. And about three-quarters of key suppliers provide just-in-time delivery, reducing raw material inventory.
General Cable Tetla has grown increasingly flexible as a result of its continuous improvement efforts. For instance, a production schedule that previously was revised monthly now gets updated weekly. The plant also swiftly reacted to an opportunity for additional business that doubled production in three months.
Web Exclusive Best Practices
Benchmarking Is Family Affair
Like other manufacturing facilities that comprise General Cable Corp., the manufacturing plant in Tetla, Tlaxcala, Mexico, benefits from a strong corporate focus on cross-plant benchmarking. Indeed, General Cable de Latinoamerica explains that all General Cable plants are assessed annually about their performance against the 12 manufacturing principles by which General Cable operates. (Those 12 principles are safety, housekeeping (5s), use of formal systems, preventive and predictive maintenance, product quality, process capability, work order delivery, visual factory, productivity, communications, training of associates and operator led process control.) Specific metrics are assigned to each principle.
The assessments, formally called Manufacturing Excellent Audits (MEA), are performed in a cross-plant fashion. For example, General Cable Tetla plant manager Luis Rosete Gonzalez was slated to join his plant's finance manager in a trip to General Cable's manufacturing facility in Moose Jaw, Saskatchewan, Canada ( a 2005 IW Best Plants winner), in late September to perform an MEA of that facility. Similarly, the Tetla plant was audited in mid-September by another General Cable Corp. plant. The audit took two full days and included three auditors.
Plants receive multiple benefits from these audits, explains Rosete, including the most basic -- sharing best practices and learning. "We learn about other processes and other work cultures and take the best," he says. Additionally, the audits foster better communications between plants, which speeds problem-solving of common issues across facilities. Further, the metrics that comprise the audits grow more challenging each year, Rosete explains, which motivates continuous improvement.