CircuiTree - July 2008 - (Page 39)

distributing the end product into international markets with different power supplies, or end products with special conﬁgurations allowing incorporation into alternate OEM systems—such as audio components built for multiple distributors. In each of these examples, a single PCB design is used with design variants deﬁned for each speciﬁc end product. team may require his or her own format and spend time manually altering the data provided from the previous creator. This errorprone solution of manual entry into nonconsistent formats culminates in a plague on the integrity of the end product deliverable. Efficiency Problems Isolating information and unintentional masking of the ripple effect causes many hours of work for everyone in the design process. This can add up to days and weeks of manually reentering data, then having every team member double or triple check the variant deﬁnitions. Across multiple design projects, companies can waste several manmonths or more every year. This wasted time encroaches on time to market and eventually reduces the total available market for the end product. Variant Problems Ripple Through the Entire Processes When variants are used in a design process, they affect many departments within a company, and those departments are often isolated from one another. Here is a small case study illustrating how problems can ripple through the entire enterprise. Frequently, variant deﬁnitions result from customer requests that then become formalized in a product marketing requirement document. This document is then passed to the system engineer who may create the variant requirement speciﬁcation. From here the design engineer responsible for the electrical behavior identiﬁes how the change could occur and then informs procurement. The information that is passed along includes depopulation and new component needs and then is moved to the responsible party in charge of ﬁnal assembly. A representation of this is made clearly visible in Figure 1. Figure 2 Variant Definition From the Schematic Environment Automating Documentation By utilizing the capability within certain EDA design tools that are speciﬁcally focused on design variant deﬁnition, companies can automate data passing across design domains in a consistent format and an automated fashion. A number of vendors offer the ability to consistently create design variant data for all downstream requirements. These products allow the deﬁnition of each variant from the schematic environment and cover generation of BOMs. Figure 3 Variant Definition From the Layout Environment essary. The newest variant managers additionally allow the design team to organize information either using traditional Physical Managed or now Functional Managed Variant deﬁnition modes during the planning stages for maximum design efﬁciency. Also, concurrent deﬁnition capability allows for maximum ﬂexibility. Enhanced and Automated Variant Documentation Incorporating these tools into the process allows distribution of variant data to all concerned parties in the product design. In addition to the advantage of eliminating errors, time, and manual data circulation, new capabilities become available for the design variant process. One of these enhanced capabilities is concurrent variant deﬁnition by multiple team members. Adding this capability to an already robust process design environment allows the product design team to better control when, why, and how variants are deﬁned in addition to who is responsible for creating them. The ability to access variant data from both the schematic and layout tools is shown in Figure 2 and 3. As the requirement of deﬁning even more complex design variants increases, a variant manager function becomes even more nec- Summary Creating an optimum variant design strategy requires companies to utilize the automation offered by EDA tools that allows variant definition during the upfront electrical design phase. This allows consistent BOMs and other viewable data to move downstream to procurement, ﬁnal assembly, and documentation for seamless debugging. By investing and deploying tools with built-in variant management and process control capabilities to move variant data to all upstream and downstream processes, companies can see up to multiple manmonths of time removed across existing design cycles, including the non-engineering impact. ■ John Peloso is an application engineer consultant, Mentor Graphics. Email: john_peloso@mentor.com circuitree.com • July 2008 39 Figure 1 Review of the Ripple Effect When Creating a Design Variant Traditional Documentation Solutions Many methods are currently used to effectively document all the variant information during each step. Combining email conversations, spreadsheets, notes on the schematic or PCB drawings, and overriding attributes on the schematic or PCB elements make up most of the documentation approaches in use today. Other approaches include physically copying and altering existing designs, then saving with a new ﬁlename. In addition, each member of the design http://circuitree.com

Table of Contents Feed for the Digital Edition of CircuiTree - July 2008

CircuiTree - July 2008 Contents My Line Industry Review Tech Talk Flexible Thinking Toward a PCB Production Floor Metric for Go/No Go Testing of Lossy High-Speed Transmission Lines Intelligent Design 20-Year Retrospective Ask the Flexperts Environmentally Speaking BPA Growth Curves Considering Design Variants to Maximize Process Efficiency Market Outlook Technical Product Spotlights Classified Ads Upcoming Events Ad Index

CircuiTree - July 2008

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