Call for Participation in the SEMI Standards Wait Time Waste Task Force for New Standards Development

Call for Participation in the SEMI Standards Wait Time Waste Task Force for New Standards Development

By Jackie Ferrell and Lance Rist (SEMI “WTW” Task Force Leaders)

Dear Colleagues,

After several years of industry discussion, study, development, and proof of concept at ISMI/SEMATECH, the SEMI Standards Metrics committee during the N.A. Standards Fall 2012 Meetings at SEMI Headquarters approved the formation of a “Wait Time Waste” (“WTW”) Task Force to develop an industry standard, Specification for Measurement of Product Time in Semiconductor Manufacturing. Participation from device makers, equipment suppliers, automated material handling system (AMHS) suppliers, and software solutions providers are needed to ensure that the standard serves the needs of SEMI Standards members and reflects current practices in the industry.

The primary goal of the Wait Time Waste metrics and methods development is to support measurement and reduction of wasted time in the product life cycle. Note that we call it “Wait Time Waste,” but there is potential waste in both wait time and active time.

It has been estimated that “wafers spend more than 93% of their time in the fab waiting without action.” [i] The value of a day of cycle time has been estimated to range between $14 million to $112 million dollars depending on a device maker’s business model, and one day of cycle time improvement has been estimated to increase gross margin dollars by 0.29% to 1.29%.[ii]

This Standard will define time elements to classify the active and wait time of a lot or wafer throughout the manufacturing life cycle. A mapping of standard events used to identify the start and end of each time element will be included in the document. The method enables log data to be filtered, translated, and expressed in a form the can be analyzed to identify time waste. The initial standard will address equipment “WTW” metrics. Development of AMHS “WTW” metrics will follow.

Standard methods provide a common approach for measurement and communication between suppliers and customers. Device makers will be able to use this method to find hidden waste within their equipment and fab operations. Equipment and AMHS suppliers will be able to use this method for design optimization or remote investigation of suspected waste, and work with device makers on analysis and potential solutions. In-house systems and commercial software products and services based on standardized metrics enable fab wide solutions that will significantly reduce the time and cost to identify waste.

This is an opportunity for those who can benefit from the standard to help determine the content and method. If you are interested in participating in the Wait Time Waste task force, the Metrics committee or would like more information, please contact Michael Tran from SEMI or the task force leaders.

 We look forward to working with you.

Jackie Ferrell and Lance Rist (SEMI “WTW” Task Force Leaders)


Contact Information:

Jackie Ferrell
International SEMATECH Manufacturing Initiative (ISMI)
257 Fuller Road Suite 2200 - Albany New York 12203
Tel +1 518-649-1208

Lance Rist
Risttex, Austin, TX



[i] Eliminating Waste: A Roadmap for Semiconductor Industry Productivity Growth, E. Englhardt, S. Koshti, and V. Shah, IEEE: ISSM Paper: MC-O-228

[ii] Economic Value of Cycle Time (EV of CT), Denis Fandel (ISMI) and Scotten Jones (ICKnowledge), ISMI Member Company Webinar, Oct. 25, 2010

SEMI, Standards Watch - May 2013