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Upgrading Database Improves Performance
Careful planning helped ensure a manufacturing site's smooth transfer from an aging system to Windows Advanced Server and SQL Server.
by John Zipperer

Posted November 6, 2003

In some projects, time is the central factor; it is involved in the problem, the solution, and the challenge along the way. For computer hard drive manufacturer Western Digital, several months of work would go into a server switchover that could take no longer than 48 hours (see Executive Summary). That was the total amount of time the company was willing to spare in the manufacturing process. But the main reason for making the switch in the first place was that the company's existing server setup was introducing a time lag that was about five times longer than the acceptable speed. With production in its overseas plants expected to increase further, that time lag would be a real and increasing problem.

With 10,000 employees, the Lake Forest, Calif.-based company has sales offices around the globe, but its manufacturing facilities are in Malaysia and Thailand. Two years ago, when Western Digital realized it needed to change the server and database setup it uses to monitor and manage production at its Asian manufacturing facilities, those two countries came to play complementary roles in the high-stakes move to a new system.

The company didn't want to slow down its production line, which feeds customers in the consumer and enterprise markets. Western Digital designs and manufactures hard drives for personal computers, Apple Macintosh computers, gaming consoles, and appliances ranging from video recorders to set-top boxes for cable and satellite systems. It also produces a line of Raptor SATA drives for the enterprise market. With a manufacturing total of more than 40 million drives a year and billions of dollars in annual sales, the company wanted to make sure that its high-profile product line continued to roll smoothly and efficiently.

As a result, it would squeeze the entire project from conception and development through testing and deployment into three short months, with the final deployment scheduled to coincide with a preplanned plant shutdown for maintenance. All that, and a platform switch to top it off, and you could understand if the company's IT leaders were getting a little nervous about the whole thing before it was over.

Getting a Quick Look at Manufacturing
Western Digital relies on an internally developed manufacturing execution system (MES) called MITECS, which continuously keeps tabs on the state of the factory floor and helps the facility keep to the manufacturing plan. MITECS' reach is far and wide; it supports about 6,000 scanning devices as well as more than 100 application-host machines that are managing and watching over the production process.

The scans provide reports on whether the right actions are being taken by the machines that install components or select software to test. Those machines query the database for confirmation, then they move the hard drive on to the next stage of production.

Thousands of hard drives are making their way through production at any given time, so the scanning and confirmations have to happen quickly. Sin Chee Pang, Western Digital's senior IT director for Asia, says that the high-volume, high-speed production creates a high possibility for mix-ups. "Any slowdown in the response time—any error—means we take a hit to our bottom line," he says.

Furthermore, the production process is a seven-days-a-week effort, with utilization rates of more than 90 percent. When it is in full production mode, MITECS accesses a database that has to be able to handle between 800 and 900 connections and more than 1,390 transactions every second.

The top transaction rate for the database connections is about 12,000 per minute. The database that MITECS accesses holds about 150 tables, the largest of which has about 60 million rows.

Meanwhile, the database feeds data to another internally developed system, the Online Digital Nervous System (DNS), which provides regular and as-needed production reports for managers throughout Western Digital. (They access realtime dashboards to get scorecards on the manufacturing process.) All of this monitoring and reporting needs to be carried out without introducing more than minimal latency into the production process.