DI:14.2 DESIGN FOR ASSEMBLY (DFA)These techniques attempt to simplify products to ease the assembly process, without compromising functionality of the product.First, consider the basic steps involved in assembly,1a. parts are purchased, and put into inventory, or storage bins.1b. parts are manufactured, and put into inventory, or storage bins.2. batches of parts are often inspected for quality.3. the batches are moved to the work station.4. the partially completed assembly may be already at the work station, or the operator may accept it from another source (e.g., a belt on an assembly line)5. the part base will be set in position.6. The operator will pick a part from the parts bin.7. the operators will (if not already) position the part correctly in their hand, and prepare to insert it into the work.8. The operator will guide the part into the final position.9. The operator will move the two parts so that they fit together10. The operator will perform any fastening operations required.11. Additional alignment or quality inspection steps may sometimes be included.Each one of these steps has potential for problems, or improvement. For example, if one part can be modified to match another, we cut the need to perform steps 1 to 5 in half. For each part that can be eliminated we reduce steps 1-11.One report of these techniques applied to circuit boards [Boothroyd and Knight, 1993] reports,- manufacturing costs down almost 20-30%- component costs down 10-20%- component counts down almost 25-40%- board densities down almost 5-20%- problem parts down over 20-90%- yield up over 30-50%DI:14.2.1 Design rule summaryPart Design1. Eliminate/minimize tangling between parts in feeders.2. Use symmetry to reduce the orientation time during handling3. If symmetry is not possible, use obvious features to speed orientationProduct Design1. Reduce the number of parts when possible2. Build the part in layers from the top on the bottom, using gravity to locate parts3. Have the already assembled product stable on the work surface4. Have the work lie in a horizontal plane5. Use chamfers and fillets to ease mating of parts.6. Use snap-fits, and other quick fasteners, avoid screws, glue, etc.DI:14.2.2 Rules for Manual/Automatic AssemblyThe basic strategies of DFA for automated assembly are,1. Reduce the number of parts2. Allow assembly from the top of a fixtured part3. Develop symmetry for easy part orientation4. Use guides to simplify part mating, such as chamfers5. Aim for snap-fit connectors, avoid screws6. Reduce handling problemsThe basic rules of DFA for manual assembly are,1. the number of parts should be reduced2. parts should be standardized where possible3. alignment operations should be reduced4. locating and aligning features should be used5. allow clear paths for parts being added to the assembly6. add orientation features so that parts can only be assembled in the correct orientations7. consider part feeding/picking from batches8. introduce symmetries to reduce the need for reorientation9. add orientation features to simplify orientation identificationDI:14.2.3 Reducing the Number of PartsDesigns often include more parts than are necessaryA set of questions must be satisfied for any two parts in an assembly to justify their being separated1. Do the parts move relative to one another?2. Must the parts be made of different materials?3. Must the parts be separable for maintenance or manufacture?Some simple ideas possible are,1. Instead of attaching labels on plastic parts, add the lettering into the mold so that the letters are added at the time of molding. The completely eliminates a part, and the associated operations.

2. In sheet metal parts create features using sheet metal, instead of attaching them with other means. Some examples are,- instead of adding hook to a sheet metal part, cut and bend hooks out of the sheet metal- don't add screw standoffs to metal, but punch the metal to create a standoff, and tap the hole.-3. When possible use snap fits instead of screws. Most screwed connectors require 1 nut, 1 bolt, typically 2 or more washers, and possibly a lockwasher, as well as a great deal of time and dexterity to assembly. Snap fittings can be made very simple and fast. NOTE: press fits can also be considered for these operations, although their need for higher forces can be a negative.

4. If screws must be used try integrating washers with the screw heads, this will eliminate at least one part.

5. Replace separate springs with parts with thin sections that act as springs.

6. When screws are required (often for maintenance) try to reduce the number to a minimum.7. Cables can be eliminated for a reduction in cost, and an increase in reliability, and access for maintenance. Card edge connectors, and PCBs will be slightly higher in material costs, but the boards are simply plugged together. If cables are strung between boards and other boards/components, they will require additional time for soldering, be the source of soldering quality problems, and make the boards tricky to orient, etc.DI:14.2.4 Feeding and Orienting PartsIt must be considered that more complicated parts require greater handling time to properly orient them.DI:14.2.4.1 - Part Tangling/NestingIt should be considered that when small parts are shipped, they come in bulk lots. (large/more expensive parts are often shipped in pallets, or separately.When the parts are stored together, they can sometimes tangle or nest.Tangling - the parts get looped together, making them difficult to separateNesting - one part gets stuck inside another, much like styrofoam cups.The obvious problem with this situation is that the parts often require additional costly human intervention to separate them, and this problem will greatly reduce the success of an automated parts feeder.The problems of nesting and tangling can be significantly reduced through small design modification in many cases.A few of the problems, and some possible solutions are shown,

DI:14.2.4.2 - Handling PartsAs parts vary greatly in size we must how it is to be manipulated. The basic categories are,

Other factors to consider when handling parts,- are the parts sticky?- are the parts fragile?- are there any sharp edges?- do the parts nest or tangle?- are there any parts or tools that the operator must leave the work station to get?DI:14.2.4.3 - Orienting PartsWhen parts are to be fed, automatically and by human, the task is simplified if certain features are added.Basically, symmetry is a major problem for automated feeders.In general, a part is easier to orient if,1. The orientation is based on internal features, and there are external features that can be used for reference.2. Extra features are added to change the centre of mass, or create holding points for features.Some examples of parts orientation are,

DI:14.2.4.4 - Locating and Aligning PartsWhen we try to thread a needle, the thread is smaller than the hole in the needle, but this does not make threading the hole simple. In fact the process of threading the needle is simplified by the rounded opening on the needle. If the opening of the needle were square it would greatly complicate this problem.Much like threading a needle, the problem of mating two parts can be simplified if the parts tend to align and locate themselves.If we consider that for one part to mate with another, it must travel along an approach axis. In fact, when the parts are mated the parts will have common axis. We can add guides to the parts to align the axis to be parallel, and to locate the axis so that they are colinear. Hence, the terms aligning and locating.Consider the cases given below, and the implications they have for alignment

Although screws are discouraged in DFA techniques, when they must be used, then we can add some features to help align and locate them.

DI:14.2.4.5 - Part SymmetryPerfectly symmetrical parts need no rotation to orient them, completely asymmetrical parts require at most 360 rotation followed by a second 360 to put them in the same position every time.There is also a recognition phase required by humans for every orientation. Therefor parts that are not symmetrical, but look as if they are upon quick inspection, will require additional inspection time.consider the cases below,

Alpha symmetry is the largest angle a part would have to be turned about an axis perpendicular to the insertion axis.Beta Symmetry is the largest angle the part would have to be rotated about the insertion axis for mating.Alpha and Beta symmetry actually range from 0 to 360 (instead of the intuitive 0 to 180) because it is assumed that the worst case rotation is used.

DI:14.2.4.6 - Part Shape, Size and ThicknessWe must consider the basic shapes of the parts being assembled. Two basic categories are prismatic and rotational.Rotational parts tend to roll when placed on a surface, suggesting that they will need some sort of holding fixture. This also means that during assembly, they must be supported by hand if not in a stable position when working.Prismatic parts tend to have at least one stable orientation that allows them to be rested on surfaces. Unlike rotational parts. If the prismatic parts are made to be stable when put in their final position, then they are much easier to fasten.The size of an object is generally the size of its largest major dimension, and thickness is the smallest major diameter.There are a number of criteria that can be used to determine how easily a part can be handled,- a high size/thickness can be a measure of fragility- large size values can indicate large weights- small size values can indicate the need for special toolsDI:14.2.5 Mating PartsThere are a large number of methods for assembling parts. Generally a fastening operation is involved.The best rule of thumb is that all assembly work is best done by setting down a large base, and slowing dropping more parts on top of the base. Each part should be fed by gravity, and the work base should not have to be moved to put the part on.When mating two parts there are a number of possible combinations. The following table is an adaptation of Boothroyd [1979].

If a part must be supported or held down by hand while a fastening operation is done, this greatly complicates any operations. If this is the case, self securing parts should be used.parts may also exert some sort of resistance to insertion. If this is the case, the force should be minimizedThere are two type of obstructions that must be considered during assembly operations- the operator has no clear view of the assembly site- the assembly site is not in easy reach (i.e. the assembly axis is not clear)A self nesting or self fixturing part is ideal. In effect the part will hold itself in location after it has been positioned.DI:14.2.6 AdjustmentsAs an assembly is built, adjustments are commonly used to bring the shape back to proper specification. This can easily by the result of errors accumulated as parts are added in discrete steps.This problem can best be avoided by,- having parts positioned relative to one reference piece. For example pilots through layers of the work can be used for mounting parts.- screw hole slots, instead of holes can allow play in position.- loosen tolerances to the minimum levels-DI:14.2.7 Modular AssembliesDesigning in modules will allow reduction of the problems involved with any one assembly.Each module should be functionally separate from the other modulesA module should have docking features to allow it to be connected to the main assemblyadvantages,- simplified assembly steps- easier quality control- simpler inventory- easier to reconfigure a system- suited to automatic assembly- fewer adjustments are required on final parts- simplified maintenanceDI:14.2.8 Standard PartsThere are a few distinct benefits to standards parts (as opposed to custom designed),- lower development costs- simple selection of vendors- lower production costs (no special tooling required)- quality levels are well established- these parts are easy to approve for Acceptance Sampling programs- automation tooling is available for many standard partsDI:14.2.9 Part Fixtures and JigsJigs and fixtures are often used when,1. Doing manual assembly, with small or fragile parts2. doing any form of robotic assembly (at present sensors are not yet available for reliable fixtureless work).3. when designing self fixturing parts where the base part also acts as a form of fixture.When parts are mounted on fixtures, we can pretend this is another assembly step, and apply all of the normal DFA rules.The location of the part on the fixture is important for both alignment, and location in many cases, as the fixture has been set up as a reference.For high accuracy in location, we are better to have (one, two, or three) point contact between the fixture and the part. For orientation, surface/surface contact (such as chamfered hole shaft pairs) will give better results.

DI:14.2.10 Bottom Up Layered AssembliesThe assembly should be done using a heavy and stable base piece at the bottom.As the design continues we want to add new parts in layers.The docking location for the new part should be a sort of mini fixture.Pilots should be added to locate layered pieces.This method also allows many parts to be put in place, and then a number of parts assembled in one assembly step.DI:14.2.11 ExamplesFirst, review the DFA handbook paying special attention to the work sheets and the tables.Use the DFA handbook a) To do an analysis of the assembly below (assume dimensions with an overall length of about 8"). b) do a redesign of the assembly and reanalyze.

DESIGN FOR MANUFACTURABILITY / ASSEMBLY WORKSHOP

DRM Associates

2006 DRM Associates

DRM AssociatesNew Product Development TrainingTraining ExperienceDFM ConsultingPD Toolkit (DFA Software)Mistake-Proofing By Design WorkshopDesign for Manufacturability PaperDesign for Assembly GuidelinesDesign for Manufacturability GuidelinesDesign for the Life CycleDesign for the EnvironmentProduct Development ForumNPD Body of Knowledge

Practical, hands-on workshop.Includes over 240 examples of good and bad design for manufacturability and assembly practices.Includes exercises to reinforce understanding of principles and analysis of company assemblies to transition learning back to your workplace. The three-day workshop includes one day on-site prior to the workshop to customized it to your products and processes.

1. DESIGN FOR MANUFACTURABILITY/ ASSEMBLY (DFM/A)

DFM/A IntroductionDesign Impact on CostDFM/A Fallacies vs. Reality2. DESIGN FOR ASSEMBLY

Principles of Design for AssemblySimplify Product ArchitectureModularity and Structure with ArchitecturePartitioning, Collocation, and Orientation Effect on InterconnectionsModular Design vs. Integral DesignSimplicity - Minimize Part CountMinimize Parts ExerciseStandardization - Minimize Part VarietyStandardization Approach and MethodMistake-Proof Assembly - The Six Mistake-Proofing Principles and the Relative BenefitElimination Principle and ExamplesReplacement Principle and ExamplesPrevention Principle and ExamplesFacilitation Principle and ExamplesDetection Principle and ExamplesMitigation Principle and ExamplesMistake-Proofing Approach and MethodologyMistake-Proofing Exercise - Identify Mistake-Proofing OpportunitiesAssembly Process FrameworkDesign for Parts Feeding & HandlingDesign for Part OrientationConsidering and Applying Symmetry vs. AsymmetryMeasuring Symmetry - Alpha, Beta and Combined SymmetryDesign for Location and Insertion Minimize Flexible PartsDFA Considerations with Gaskets, Interconnections, & ConnectorsAxes of Assembly, Reorientation & Blind AssemblyTop Down, Uni-Axis AssemblySelf-Fixturing vs. Production FixturesJoining & Fastening GuidelinesIntegral Attachment (Self-Fastening & Snap-Fit Assembly) GuidelinesThreaded Fastener Considerations & GuidelinesAdhesive Joining GuidelinesWelding GuidelinesOther Fastening Methods and GuidelinesFinishing, Adjustment & CalibrationDFA Considerations to Facilitate Test and InspectionApplying DFA to Packaging - The Final Assembly StepCase Studies and Benefits - Aerospace, Automotive, Electronics, Mechanical MachineryDesign for Assembly Analysis Exercise2. DESIGN FOR AUTOMATED ASSEMBLY (optional module)

Production Considerations for Manual, Flexible Automation and Hard AutomationCost / Benefit Analysis of AutomationDesign for Feeding GuidelinesFeeding Systems & OrientationFlexible AutomationDesign for Robotic Assembly GuidelinesDesign for Vision System GuidelinesGripper Design Guidelines3. DFM/A FOR ELECTRONICS

Use of DFM/A Guidelines for BoardsSimplify the Assembly Process - Mixing Technology and Board SidesReduce Thermal CyclesBoard Size and Panelization GuidelinesPCB Layout GuidelinesPanel Considerations and Keep-Out AreaTooling HoolsFiducialsThrough-Holes and ViasTrace Width and SpacingPad Layout and Component SpacingTest Point AccessComponent Selection GuidelinesAvoid Manual AssemblyOther Component ConsiderationsDFM/A Assessment for BoardsAutomated Design Rules Checking4. DESIGN FOR MANUFACTURABILITY

DFM FrameworkMaterial and Process EvaluationMaterial and Process Evaluation ExerciseRaw Material StandardizationGeneral DFM GuidelinesMachining Guidelines and ExamplesManufacturability Analysis ExerciseSheet Metal Guidelines and ExamplesInjection Molding Guidelines and ExamplesCasting Guidelines and ExamplesMinimize Finishing Requirements5. PROCESS CAPABILITY AND TOLERANCES

What is Process CapabilityVariation and SpecificationsParameter and Tolerance ObjectivesStatistical Process CapabilityNormal DistributionCapabilities Indices - Cp and CpkCapability Index ExercisesSix Sigma Capability and Defects per MillionEffect of TolerancesTolerance AnalysisWorst CaseRoot Sum of Squares (RSS)Tolerance Optimization6. DESIGN FOR "X" (Optional topics covered on request)

Design for the Supply ChainDesign for LeadtimeDesign for SafetyDesign for Human FactorsDesign for ReliabilityDesign for DisassemblyDesign for Serviceability/MaintainabilityDesign for the Environment (DFE)DFE Examples & Case Study7. DFM/A AND THE DEVELOPMENT PROCESS

DFM/A Process StepsDuring Concept Development PhaseDuring Design PhaseDuring Validation and Pilot PhaseDuring Production Launch PhaseEarly Manufacturing InvolvementDFM/A Collaboration Tools and MethodsRole of Solids and Assembly Models in DFM/A EvaluationHow to Effectively Consider Design Alternatives to Address DFM/A IssuesProduct Cost Models to Estimate Costs & Evaluate Design AlternativesEarly Supplier InvolvementDeveloping Design GuidelinesFormal DFM/A Analysis & AssessmentDFM/A Manual and Software ToolsConducting Design Reviews to Address DFM/ACapturing Issues with Build ReportsClosing the Loop with a Final Production ReviewDFM/A Performance Measurement & Metrics8. SUMMARY

10 Steps to DFM/ADFM/A Survey ResultsSources of Further InformationQuestions and Discussion9. DFM/A ANALYSIS OF COMPANY PRODUCT OR ASSEMBLY

Transitioning from the Workshop to Product Design - Exercise ObjectivesIntroduction of Analysis Methodology and DFM/A WorksheetTeam Analysis of Company Products or AssembliesTeam Consideration of DFM/A ImprovementsTeam Reporting Out and Exercise DiscussionConcluding Questions and Discussion

DESIGN FOR MANUFACTURABILITY / ASSEMBLY GUIDELINES1. Simplify the design and reduce the number of parts because for each part, there is an opportunity for a defective part and an assembly error. The probability of a perfect product goes down exponentially as the number of parts increases. As the number of parts goes up, the total cost of fabricating and assembling the product goes up. Automation becomes more difficult and more expensive when more parts are handled and processed. Costs related to purchasing, stocking, and servicing also go down as the number of parts are reduced. Inventory and work-in-process levels will go down with fewer parts. As the product structure and required operations are simplified, fewer fabrication and assembly steps are required, manufacturing processes can be integrated and leadtimes further reduced. The designer should go through the assembly part by part and evaluate whether the part can be eliminated, combined with another part, or the function can be performed in another way. To determine the theoretical minimum number of parts, ask the following: Does the part move relative to all other moving parts? Must the part absolutely be of a different material from the other parts? Must the part be different to allow possible disassembly?

2. Standardize and use common parts and materials to facilitate design activities, to minimize the amount of inventory in the system, and to standardize handling and assembly operations. Common parts will result in lower inventories, reduced costs and higher quality. Operator learning is simplified and there is a greater opportunity for automation as the result of higher production volumes and operation standardization. Limit exotic or unique components because suppliers are less likely to compete on quality or cost for these components. The classification and retrieval capabilities of product data management (PDM) systems and component supplier management (CSM) systems can be utilized by designers to facilitate retrieval of similar designs and material catalogs or approved parts lists can serve as references for common purchased and stocked parts.

3. Design for ease of fabrication. Select processes compatible with the materials and production volumes. Select materials compatible with production processes and that minimize processing time while meeting functional requirements. Avoid unnecessary part features because they involve extra processing effort and/or more complex tooling. Apply specific guidelines appropriate for the fabrication process such as the following guidelines for machinability:

For higher volume parts, consider castings or stampings to reduce machiningUse near net shapes for molded and forged parts to minimize machining and processing effort.Design for ease of fixturing by providing large solid mounting surface & parallel clamping surfacesAvoid designs requiring sharp corners or points in cutting tools - they break easierAvoid thin walls, thin webs, deep pockets or deep holes to withstand clamping & machining without distortionAvoid tapers & contours as much as possible in favor of rectangular shapesAvoid undercuts which require special operations & toolsAvoid hardened or difficult machined materials unless essential to requirementsPut machined surfaces on same plane or with same diameter to minimize number of operationsDesign workpieces to use standard cutters, drill bit sizes or other toolsAvoid small holes (drill bit breakage greater) & length to diameter ratio > 3 (chip clearance & straightness deviation)Example of DFM guidelines for sheet metal

4. Design within process capabilities and avoid unneeded surface finish requirements. Know the production process capabilities of equipment and establish controlled processes. Avoid unnecessarily tight tolerances that are beyond the natural capability of the manufacturing processes. Otherwise, this will require that parts be inspected or screened for acceptability. Determine when new production process capabilities are needed early to allow sufficient time to determine optimal process parameters and establish a controlled process. Also, avoid tight tolerances on multiple, connected parts. Tolerances on connected parts will "stack-up" making maintenance of overall product tolerance difficult. Design in the center of a component's parameter range to improve reliability and limit the range of variance around the parameter objective. Surface finish requirements likewise may be established based on standard practices and may be applied to interior surfaces resulting in additional costs where these requirements may not be needed.

5. Mistake-proof product design and assembly (poka-yoke) so that the assembly process is unambiguous. Components should be designed so that they can only be assembled in one way; they cannot be reversed. Notches, asymmetrical holes and stops can be used to mistake-proof the assembly process. Design verifiability into the product and its components. For mechanical products, verifiability can be achieved with simple go/no-go tools in the form of notches or natural stopping points. Products should be designed to avoid or simplify adjustments. Electronic products can be designed to contain self-test and/or diagnostic capabilities. Of course, the additional cost of building in diagnostics must be weighed against the advantages.

6. Design for parts orientation and handling to minimize non-value-added manual effort and ambiguity in orienting and merging parts. Basic principles to facilitate parts handling and orienting are:

Parts must be designed to consistently orient themselves when fed into a process.Product design must avoid parts which can become tangled, wedged or disoriented. Avoid holes and tabs and designed "closed" parts. This type of design will allow the use of automation in parts handling and assembly such as vibratory bowls, tubes, magazines, etc.Part design should incorporate symmetry around both axes of insertion wherever possible. Where parts cannot be symmetrical, the asymmetry should be emphasized to assure correct insertion or easily identifiable feature should be provided.With hidden features that require a particular orientation, provide an external feature or guide surface to correctly orient the part.Guide surfaces should be provided to facilitate insertion.Parts should be designed with surfaces so that they can be easily grasped, placed and fixtured. Ideally this means flat, parallel surfaces that would allow a part to picked-up by a person or a gripper with a pick and place robot and then easily fixtured.Minimize thin, flat parts that are more difficult to pick up. Avoid very small parts that are difficult to pick-up or require a tool such as a tweezers to pick-up. This will increase handling and orientation time.Avoid parts with sharp edges, burrs or points. These parts can injure workers or customers, they require more careful handling, they can damage product finishes, and they may be more susceptible to damage themselves if the sharp edge is an intended feature.Avoid parts that can be easily damaged or broken.Avoid parts that are sticky or slippery (thin oily plates, oily parts, adhesive backed parts, small plastic parts with smooth surfaces, etc.).Avoid heavy parts that will increase worker fatigue, increase risk of worker injury, and slow the assembly process.Design the work station area to minimize the distance to access and move a part.When purchasing components, consider acquiring materials already oriented in magazines, bands, tape, or strips.7. Minimize flexible parts and interconnections. Avoid flexible and flimsy parts such as belts, gaskets, tubing, cables and wire harnesses. Their flexibility makes material handling and assembly more difficult and these parts are more susceptible to damage. Use plug-in boards and backplanes to minimize wire harnesses. Where harnesses are used, consider foolproofing electrical connectors by using unique connectors to avoid connectors being mis-connected. Interconnections such as wire harnesses, hydraulic lines, piping, etc. are expensive to fabricate, assemble and service. Partition the product to minimize interconnections between modules and co-locate related modules to minimize routing of interconnections.

8. Design for ease of assembly by utilizing simple patterns of movement and minimizing the axes of assembly. Complex orientation and assembly movements in various directions should be avoided. Part features should be provided such as chamfers and tapers. The product's design should enable assembly to begin with a base component with a large relative mass and a low center of gravity upon which other parts are added. Assembly should proceed vertically with other parts added on top and positioned with the aid of gravity. This will minimize the need to re-orient the assembly and reduce the need for temporary fastening and more complex fixturing. A product that is easy to assemble manually will be easily assembled with automation. Assembly that is automated will be more uniform, more reliable, and of a higher quality.

9. Design for efficient joining and fastening. Threaded fasteners (screws, bolts, nuts and washers) are time-consuming to assemble and difficult to automate. Where they must be used, standardize to minimize variety and use fasteners such as self threading screws and captured washers. Consider the use of integral attachment methods (snap-fit). Evaluate other bonding techniques with adhesives. Match fastening techniques to materials, product functional requirements, and disassembly/servicing requirements.

10. Design modular products to facilitate assembly with building block components and subassemblies. This modular or building block design should minimize the number of part or assembly variants early in the manufacturing process while allowing for greater product variation late in the process during final assembly. This approach minimizes the total number of items to be manufactured, thereby reducing inventory and improving quality. Modules can be manufactured and tested before final assembly. The short final assembly leadtime can result in a wide variety of products being made to a customer's order in a short period of time without having to stock a significant level of inventory. Production of standard modules can be leveled and repetitive schedules established.

11. Design for automated production. Automated production involves less flexibility than manual production. The product must be designed in a way that can be more handled with automation. There are two automation approaches: flexible robotic assembly and high speed automated assembly. Considerations with flexible robotic assembly are: design parts to utilize standard gripper and avoid gripper / tool change, use self-locating parts, use simple parts presentation devices, and avoid the need to secure or clamp parts. Considerations with high speed automated assembly are: use a minimum of parts or standard parts for minimum of feeding bowls, etc., use closed parts (no projections, holes or slots) to avoid tangling, consider the potential for multi-axis assembly to speed the assembly cycle time, and use pre-oriented parts.

12. Design printed circuit boards for assembly. With printed circuit boards (PCB's), guidelines include: minimizing component variety, standardizing component packaging, using auto-insertable or placeable components, using a common component orientation and component placement to minimize soldering "shadows", selecting component and trace width that is within the process capability, using appropriate pad and trace configuration and spacing to assure good solder joints and avoid bridging, using standard board and panel sizes, using tooling holes, establishing minimum borders, and avoiding or minimizing adjustments.

ABOUT THE AUTHOR

Kenneth A. Crow is President of DRM Associates, a management consulting and education firm focusing on integrated product development practices. He is a distinguished speaker and recognized expert in the field of integrated product development. He has over twenty years of experience consulting with major companies internationally in aerospace, capital equipment, defense, high technology, medical equipment, and transportation industries. He has provided guidance to executive management in formulating a integrated product development program and reengineering the development process as well as assisted product development teams applying IPD to specific development projects.

He has written papers, contributed to books, and given many presentations and seminars for professional associations, conferences, and manufacturing clients on integrated product development, design for manufacturability, design to cost, product development teams, QFD, and team building. Among many professional affiliations, he is past President and currently on the Board of the Society of Concurrent Engineering and is a member of the Product Development Management Association and the Engineering Management Society. For further information, contact the author at DRM Associates, 2613 Via Olivera, Palos Verdes, CA 90274, telephone (310) 377-5569, fax (310) 377-1315, or email at kcrow@aol.com.