Design Guidelines and ChecklistDesign Guideline Benefit Minimize Number of Parts Lower volume of drawings and instructions to control Lower assembly error rate Higher consistency of part quality Higher rate of reliability Minimize Number of Part Numbers Lower assembly error rate Eliminate Adjustments Higher first-pass yield Lower failure rate Make assembly Easy and Error-proofed Lower assembly error rate Lower assembly error rate Lower assembly error rate Lower assembly error rate Less damage to parts; better serviceability Use Repeatable, Well Understood Processes Higher part yield Higher assembly yield higher reliability Eliminate Engineering Changes on Released Products Lower assembly error rate . less unnecessary rework Lay Out Parts for Reliable Process Completion Higher yield.Choose Parts that can Survive Process Operations Higher yield Higher reliability Design for Efficient and Adequate Testing Truer assessment of quality. g. tolerance on flange flatness-is this achievable at low cost or is additional machining required? — Has an Error Proofing for Manufactuirng analysis been completed for the design..33 will necessitate change of designs/process) — Has known history/experience been reviewed? (warranty data. . design manual) — Has a parts standardization analysis been done? — Are possible tolerances the maximum that are possible? — Are new assembly methods/processes agreed with manufacturing/ — Are materials and components suitable for the fabrication method chosen. capable? — What are the Cpk values? (any <1. e.Design for Manufacturability Checklist — Has a cross-functional team meeting been held involving all relevant members? (List the members) — Have all significant characteristics been identified? — Are all processes to be used. Design for Assembly Checklist — Will the proposed design fit the space envelope given by the customer without violating minimum allowed clearances? — Has welded access been ensured? — Have mating surfaces been minimized? — Has access for assembly tools been ensured? — Is the project an International project? — Are there different manufacturing processes in different involved plants? — Has the lead manufacturing team leader been identified? — Are the specified materials available in all the involved countries? — Which plant is coordinating the ordering of the material? . Design for Assembly Checklist. Continued Materials — Do weld materials and process conform to the approved standards? — Are anti-corrosion properties adequate to give desired service life in the given service conditions? — Is the formability of the material appropriate for the manufacturing process? — Is the cost of the material justified by its material properties/application? — Are leakage specifications capable for applicable manufacturing process? Recyclability — Is E Glass filling feasible with automatic equipment (exhaust)? — Does the proposed design materials used allow recyclability to required standards? . especially if processes are different from the main assembly. • Use self tapping screws when applicable • Eliminate fasteners by combining parts. • Ensure the product’s life can be extended with future upgrades. • Use sub-assemblies. • Consider fasteners that push or snap on. • Design foundation part so that I has features that allow it to be quickly and accurately positioned. the most likely to fail-last. • Purchase sub-assemblies assembled and tested Fastening • Use the minimum number of total fasteners. • Make parts independently replaceable. • Use the minimum number of types of fasteners. • Order assembly so the most reliable goes in first. •Specify proper tolerances for press fits. • Make sure screws should have the correct geometry so that auto-feed screwdrivers are used.Assembly Strategy Guidelines • Design product so that subsequent parts can be added to a “foundation” part. • Provide unobstructed access for part and tools. • Use slotted nuts only when necessary. • Minimize use of fasteners with snap together features. • Design product so parts are assembled from above or from the minimum number of directions. • Use fewer large fasteners rather than many small fasteners. • Make sure options can be added easily. . • Standardize on types of linear materials and then cut and mark as needed. • Tests should be given adequate diagnostics to minimize repair time. plug electrical sub-assemblies directly together.Assembly Motions • Fastened parts are located before fastener is applied. • Minimize electrical cables. • Minimize the number of types of cables. • Assembly motions are simple. • Minimize the test effort spent on product testing consistent with quality goals. • Minimize the number of total parts. Part Design • Use standard parts. . • Products should not need any mechanical or electrical adjustments unless required for customer use. • Combine parts and functions into a single part. • Sub-assemblies are structured to allow sub-assembly testing. • Assembly motions can be done with one hand or a robot. • Testing can be performed by standard test instruments • Test instruments have adequate access. • Minimize the number of part types. •Assembly motions should not require skill or judgment. Test • Product can be tested to ensure desired quality. • Consider pre-finished material. • Standardize design features. Part Shape • Adhere to specific process design guidelines. • Make sure parts can be presented to automation. • Make sure parts are within automation load capacity. • Use parts that do not adhere to each other or the track. spues. • Provide drainage for parts that are plated or washed. quality and safety objectives. • Use parts that will not tangle when handled in bulk. • Design parts to easily maintain orientation. • Make sure parting lines. • Use chamfers and tapers to help parts engage. • If part symmetry is not possible. • Provide registration and fixturing locations. make parts very asymmetrical. gating or any flash do not interfere with gripping. • Tolerances are the widest consistent with functional. • Design parts with symmetry. • Specify tolerances tight enough for automatic handling. • Make sure parts are within machine gripper span. Handling by Automation • Design and select parts that can be oriented by automation. • Make sure that parts can be gripped by automation. . • Avoid right/left hand parts. • Use parts that will not shingle when fed end to end. • Avoid flexible parts which are hard for automation to handle. • Provide means to locate sub-assembly before fastening. service. • Ensure repair tasks use the fewest tools.Repair and Maintenance • Provide ability for tests to diagnose problems. or maintenance tasks pose no safety hazards. • Design products with self-test capability. • Make parts independently replaceable. • Provide inexpensive spare parts in the product. the most likely to fail . • Connections to sub-assemblies should be accessible and easy to disconnect. • Make sure that most likely tasks are easy to perform. • Make sure repair. • Provide part removal aids for speed and damage prevention. • Sensitive adjustments should be protected from accidental change. • Ensure modules can be tested. • Use quick disconnect features. • Provide unobstructed access for parts and tools. • Design products for minimum maintenance. • Protect parts with fuses and overloads. • Design self correction capabilities in to products.last. . • Access covers which are not removable should be self supporting in the open position. • Ensure any sub-assembly can be accessed. • Use modular design to allow replacement of modules. • The product should be protected from repair and damage. • Ensure that failure or wear prone parts are easy to replace with disposable replacements. • Make sure sub-assembly orientation is obvious or clearly marked. • Order assembly so the most reliable goes in first. • Ensure availability of spare parts. diagnosed and adjusted while in the product. •Revisions and changes do get documented and implemented. •Eliminate process steps that depend on operator’s memory. Error Proofing • Use standard parts. • Design parts with symmetry. • Make part differences very obvious. • Design so that omissions can not happen. • Design so that subsequent part installation will sense previous part omission. • Make sure that the wrong part cannot go into the intended position. • Design in counters and timers to aid preventative maintenance. • Design so that omissions would be easy to see during inspection. . • Design so parts can not be installed in the wrong orientation. • Include warning devices to indicate failures.• Design products with test ports. • Make sure that the part cannot go into the wrong position. • Specify key measurements for preventative maintenance. • Design so that omissions would be visually obvious. • Revisions to the product design are clearly conveyed to manufacturing and implemented. • Design so assembly or process sequence is intuitively obvious. • Make different timing very different.Error Proofing • Design so assembly or process sequence does not matter. • Clearly specify assembly or process order. • Make all timed operations the same. • Eliminate operator timed process. • Design so assembly steps can not happen in the wrong order. . • Design without the need for timed process.