Cleanroom garments: Ask questions, get what you need

09/01/2003

While establishing a program isn't "rocket science," it's a necessary and potentially expensive aspect of cleanroom operations that requires attention and understanding. Here are some practical considerations is moving forward

By Bob Spector

Having recently reviewed articles pertaining to cleanroom garments and their associated programs, it appears that certain aspects of the selection and oversight process receive little if any attention.

Ten years ago, a process engineer at Sematech publicly commented that working with cleanroom garments wasn't "rocket science." At the time, I took offense to that statement; however, as time passed, I became more comfortable with what was said. While it's not necessarily a science, it's a necessary and potentially expensive aspect of cleanroom operations that requires attention and understanding.

While previous articles have covered, in great detail, the typical costs associated with having a garment program in place, cost is not the only issue. When you sign a contract, you are typically committing your company to a minimum of three years with that supplier. But before end users step into this critical relationship, the right questions need to be asked concerning proper program-level selection and garment management before the ink touches the contract.

This month, two concerns will be covered: How to approach the "upgrade" issue and how to better understand inventory and its control within the system.

The program upgrade issue

If you're considering an upgrade to your garment program or are having an upgrade recommended, you need to ask:

• Is it necessary and cost-effective?
• Can I equate a legitimate return on my investment (ROI)?
• What potential personnel issues will arise when style and fabric types are changed?
• Are these legitimate personnel problems, or are employees resisting change?
• Do the garments I currently use meet the expectations necessary to produce product that meets the quality levels of the company and/or the customer?
• Will the garments continue to meet our needs into the near term (1 to 3 years)?
• While I know that my current garments are old, do they contribute to the failure of product?

If the answers to these questions are not totally within your area of responsibility, be sure to communicate with those employees who can supply you with the needed answers. Consider convening a committee that can openly discuss both the positives and negatives of the program. Don't be afraid to include production personnel, since they're the people who will be wearing the garments the most. If this is the approach you have chosen, remember not to lose sight of quality standards that are in place.

There is nothing wrong with not having all the answers; and remember, knowing where to get the answers is equally as important as having the answers.

Additionally, don't be afraid to pose some of these questions to your supplier's sales and/or service representative. If the recommendation is being brought forward, it should come along with proper justification.

Understanding inventory levels

The second item that needs to be understood is the inventory level necessary to accommodate personnel and how that level is managed during garment usage. There is nothing more difficult to explain to middle or upper management than why people were not able to get into the cleanroom because there were insufficient garments available.

The accuracy of sizing (fit) for your personnel, coupled with the rate in which you change your garments will determine how many sets of garments you should have available. Other considerations are whether you have ancillary operations factored in to your garment processing rotation, as well as issues of visitors, equipment field service reps, near-term personnel hiring and other miscellaneous items that apply to your facility.

The ease of increasing inventory into the loop is dependent on the style of your garment, type of fabric being used and, in some cases, size. Does or will your supplier carry inventory available for use in a relatively short period of time?

Before relying on available shelf inventory to get out of a jam, several things must be understood, including:

Was a sufficient quantity of garments by size placed into use? This would require that your personnel are properly sized, usually by trying on garments and subsequently wearing the right size.

Did you take into consideration garments that are out for repair, or other potential unplanned uses? There is nothing wrong with having a reasonable percentage available to aid in these types of scenarios. Depending on the size of your operation, 10 percent is not necessarily too high.

Most suppliers attempt to maintain inventory control by use of bar codes; additionally, suppliers can be quick to show reports that justify higher pricing, which is seen as "value added." Realistically, only a handful of reports aid in the controlling of inventory. The most valuable is a report that shows not only how many of each item was installed by size, but on a per turn-in basis—or, what percentage of that total was processed. The higher the percentage, the higher the usage, which could result in shortages. In this case, lower percentages mean that while you are probably paying for garments, they are not being used.

The use of reports should not take the place of periodic physical inventories. Having established a baseline number at the start of the program is also critical to the accuracy of future reporting. Be sure that you establish the proper size protocol, rate of change and other variables that effect usage at the outset of the contract. Changes to inventory levels, both up and/or down, can result in unexpected cost.

Remember, it's your money. Understand where it's being spent, how it's being spent and, most of all, don't forget to ask if it needs to be spent.

BOB SPECTOR is an independent consultant with more than 24 years of cleanroom experience as both a user in the semiconductor field and a supplier in the cleanroom laundry field. He is also a past president of the IEST and a current member of the CleanRooms Editorial Advisory Board. He can be reached at: [email protected]

This is Part I of what will be an ongoing series of cleanroom garment and laundry management articles offering practical management advice. Future articles will discuss such areas as fabric and garment selection, garment storage and rate of change, quality control and overall expectations.