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80 The PCB Magazine • December 2016 yields before it can be estimated accurately. Two key metrics were developed to bring about this price/performance tradeoff. They are: • Complexity Index (CI) to characterize the complexity of physical characteristics (size, lay- ers, holes, traces, etc.) of this particular PWB so that first pass yield can be calculated. • Relative Cost Index (RCI) is an artificial cur- rency that indicates the magnitude of price changes between two or more design alterna- tives. SMT Assembly The major metrics of SMT assembly are: • Assembly Report Card is a predictive and very comprehensive set of metrics. The ten (10) factors are based on a total point scheme derived from assembly costs. The points affect quoted prices to the extent: A second typical metric is assembly complexity [8,9] . This is defined as leads per square inch (LPI). The article cited provides the data for a regression model of average cost per lead versus assembly complexity. Proposed Approach Emerging assembly and fabrication CIM sys- tems such as CIMnet and CIMBridge [10] , CAD- Master and individual software solutions offer a new opportunity to implement DFM/A. These are modern frameworks that I call concurrent manufacturing (CM) to differentiate them from concurrent engineering. The framework of CM is shown in Figure 4. The important role CM plays in DFM/A is illustrated by the module Product Information Exchange (PIX). Its role is to: • Communicate information between: De- sign engineering to manufacturing; manufac- turing to design engineering and other manu- facturing; subcontractors • Automate: CAD data exchange; revision archiving • Provide: Product data tracking; packaging completeness checking; supports standard in- dustry networking • Design for Assembly: Analyzes part place- ment; supports multiple machine configura- tion; analyzes machine capacity; and provides production engineering documentation. The emerging data transfer environment is from the enterprises central data base called prod- uct data management (PDM) [11] . Figure 5 illus- trates this new data movement condition. PDM software integrates all data required to design, manufacture and support a product. Data such as: UNDERSTANDING PREDICTIVE ENGINEERING Figure 4: Concurrent manufacturing framework.