Design rules for cost-efficient cleanroom design
Cleanroom designers should follow a few simple rules to produce cost efficient designs: rely on the designers` experience and expertise, begin with investing in data recording and understanding, develop data banks and algorithms, and take a professional and responsible approach to programming, conceptual design and configuration control.
By Norbert Wiegler, B&W Projects Inc.
The cost of semiconductor fabrication plants and cleanrooms keeps skyrocketing. Today, the price tag of a state-of-the-art facility for a fab runs between $200 million and $400 million (facility only, process equipment, its installation and hook-up not included). Intel`s Gordon Moore, chairman and co-founder, predicts that the total cost of a fab (including process equipment) will reach $10 billion in the early years of the
next century. That means that the cost of next-generation fab facilities (keeping the present ratio between the total cost and the facilities cost) will reach $1 billion to $2 billion! The cost of cleanrooms for other applications, although not as high, follows the same pattern as clean manufacturing, i.e. cleanrooms are and/or become essential in a growing number of industries — biotech, pharmaceutical, medical equipment, semiconductors manufacturing equipment, etc.
Although the cleanroom`s cost is usually driven by the client`s requirements, there are ways experienced Architects & Engineers (A&Es) could minimize costs and even reverse the trend.
General design rules and prerequisites
The cost of a cleanroom is driven mainly by three factors:
Client`s requirements
A&E design
Changes of scope.
In order to be effective, the A&E must have experience in and understanding of the industry for each of the cleanrooms designed. The experience and in-depth understanding should cover not only the areas of design and construction but also the operation and maintenance of the plant facilities. This kind of experience gives the A&E the much needed authority to conduct a proper programming and project scope definition.
In addition, the A&E ought to invest heavily in building a broad database and developing algorithms for various types of cleanrooms used for different applications and industries. The database should include process equipment and its requirements, utilities matrices, data from previous projects, data of existing similar facilities, etc. The database should be compared, normalized and the proper algorithms developed. In this process, operation and maintenance experience is essential. Having this kind of data, and understanding it, gives the A&E credibility.
The quality, performance and total installed cost (TIC) of a project are defined during the first two design activities, i.e. programming or scope definition and conceptual design. Furthermore, changes of scope in any subsequent phases of a project can increase its cost. These critical activities and the main cost reduction methods are discussed below.
Programming
The programming or project scope definition phase is the most important part of a project. Here, the client states his/her intentions, requirements and sometimes, expectations. Some clients are more knowledgeable, some less. Some clients come with a written set of requirements and specifications, even concepts of the cleanroom and facilities, some do not.
However, what`s more important is that most A&E`s approach the programming as neutral brokers. This approach is wrong. The programming should be an interactive process and A&Es — instead of writing down the client`s requests — should constructively challenge these requests utilizing their industry experience and insight, data banks and algorithms. Here the A&E`s credibility and authority as an industry expert are paramount while the payback — in terms of cost efficiency — is very high.
In order to succeed, it is important to involve the client`s senior management in the programming process. Only they have the authority to make on-the-spot decisions, and they are also more cost conscious than the engineering people who set the initial requirements. The role of the A&E is to provide the decision makers with the data to make the tough decisions.
Carrying out the programming process using a well-known method, such as recording the requirements and the decisions on cards that are posted on the walls of the programming room, is recommended. Publishing a report when the programming is complete is mandatory. The report should clearly summarize the agreed upon project requirements, design criteria as well as the decisions made during the programming process. This report becomes the starting point for the next phase — the conceptual design.
Conceptual design
If the programming is the design phase at which the client has the highest impact on the project cost, the conceptual design phase is where the A&Es have the most important contribution to the quality, performance and cost of the project. Here, the A&E`s experience and expertise are critical. Although there are not “magic bullets,” there are a few rules that can help to minimize the cost of a cleanroom while optimizing its use.
One of the most efficient ways is the “modular approach.” This method is used for sizing utilities plants because most of the time the utilities requirements are not and cannot be precisely defined. It makes use of the data contained in the utilities matrices, A&E developed data banks and algorithms. It consists of optimizing the size of the plant for each project phase and designing the plant to allow for the installation of additional modules as and only when needed, without any impact on the operation of the plant.
Another proficient method for a cost efficient design is the use of trade studies for the high cost items where multiple solutions exist. This method requires an in-depth understanding of the industry combined with the knowledge of all the appropriate alternative solutions.
Change-of-scope requests
During the design development, detail design, and construction phases of a project, the main risk to a project`s cost are changes in scope. These are usually driven by the client, the contractors and, sometimes by design errors and omissions. We will discount the design errors and omissions for obvious reasons. The ways of dealing with the other change orders sources are relatively simple.
To deal with the client initiated changes, the A&E should establish a configuration control procedure from the beginning. The procedure should require approval of changes by the client`s highest level possible thus discouraging trivial change requests. Further, the procedure should direct a cost impact analysis for each change. This approach will ensure that only fitting changes will be proposed and eventually approved.
Many times the contractors request changes for various reasons such as replacing materials because of availability, ease of construction/installation, etc. The configuration control procedure should encourage those changes with positive impacts on cost and/or schedule. The same approval criteria (cost impact analysis) should apply.
Handling the change-of-scope requests in this way will reduce the number of requests and the number and negative impact of the approved changes.
Conclusions
It is possible to control a cleanrooms TIC and reduce, if not reverse, the trend of escalating costs while keeping the quality and performance of the cleanroom and its facilities at the highest levels and within the clients` requirements, design criteria and specifications. To prove this point it is worth mentioning that through careful implementation of the above described rules, the TICs of two fabs were reduced by 15 percent and 22 percent respectively compared to industry averages.
Norbert Wiegler is chief executive officer of B&W Projects Inc.( Santa Clara, CA), offering full service architectural, engineering and project management to the high technology and semiconductor industries.
Wiegler has worked in the high technology and semiconductor industries for more than 17 years. He joined B&W after working as a senior project manager at Jacobs Engineering. Prior to this, Wiegler served as senior project manager at SAIC, an R&D company, and as director of corporate facilities at Seeq Technology Inc., a semiconductor manufacturing company. Wiegler`s high-tech career began at Intel Corporation where he worked as a senior project manager and later as a site facilities manager. He has a master`s degree in mechanical engineering from the University of Jassy, Romania, and has published numerous articles regarding cleanroom technology and design. He is a member of the National Society of Professional Engineers, the American Institute of Plant Engineers and the Institute of Environmental Sciences.
Wiegler can be reached at B&W Projects Inc., 3120 Scott Boulevard, Santa Clara, CA 95054, telephone (408) 562-3560, fax (408) 562-3575.
Editor`s note: This article is reprinted from the CleanRooms East `97 Proceedings. The proceedings are available for $95; please call Nuala Kimball, CleanRooms Conferences, at (603) 891-9267.
 |
 |