Pulling the supply chain

03/01/2001

Hank Hogan

SYRACUSE, NY—While cleanrooms are often used to manufacture products, they also are products. Assembled from cleanroom panels, HEPA filters, HVAC units and other components, a finished cleanroom sits at the end of a long supply chain. And that supply chain has been whipping around.

Scott Mackler, a principal with Syracuse, NY-based Cleanroom Consulting LLC, puts the standard, conservative lead time for a HEPA filter at 10 weeks as of October 2000. Delivery of HVAC units was running 12 weeks. Cleanroom panels appeared 10 weeks after being ordered. According to Mackler, these numbers represent a bad news/good news scenario.

"In the fourth quarter of 2000, deliveries had lengthened," he remarks. "Now they're being pulled in again."

Just how much is difficult to determine. Throughout 2000, there were reports of cleanroom construction delays due to a lack of contractors and a shortage of critical components. Now, the economic slowdown may be changing that. For instance, anecdotal stories tell of scarce valves that suddenly are abundant. Valve lead times that were months are now days. Reportedly, this surge in availability is due to the sudden canceling of overseas cleanroom projects.

John Bazinet, a principal with cleanroom component manufacturer SBB Inc. (Topsfield, MA), has seen fluctuations in some basic cleanroom components.

Over the last year, the one-time stable promised delivery of HEPA filters has been anything but.

"One day you call up the vendors and they say you have to wait 12 weeks, and then two weeks later, you can get it out of stock," says Bazinet.

Manufacturers of cleanroom components are experiencing the supply chain bullwhip effect. A small change in demand by the ultimate end consumer, cleanroom users, translates into a large change as seen by the makers of filters and valves.

In semiconductor and other manufacturing, the solution is to share information about changes in market demand. In this way, the small downstream ripples don't amplify into wild upstream waves.

That smoothes out both perceived demand and actual delivery. Lead times become more predictable, and delivery can be just-in-time.

However, those approaches may not work well when manufacturing cleanrooms

"You really can't because they are specialized," says William Lynch, a Rochester, NY-based business segment leader for High Tech and Life Sciences at the engineering firm Bergmann Associates PC. "Typically, you can't just buy parts and pieces off the shelf and put a cleanroom together."

What can be done, according to Lynch and others, is extensive planning upfront. That can avoid some unpleasant surprises later, when it's discovered that the HEPA filters originally ordered won't meet regulatory requirements. Ordering the right filters then leads to a delay in the project and a postponement of cleanroom completion.