Design for Manufacturing: Part 1

Design For Manufacturing: Part 1?

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As the shipyard’s Design Build Team initiates their integration of design engineering and process planning, Design for Manufacturing (DFM) is implemented to conceptualize a vessel that is both “builder friendly” and cost efficient to the manufacture. The overall objective of DFM is to reduce the shipyard’s production cost while maintaining the operational “Mission Requirements” of the vessel.?

In addition, DFM will address the following: ?

• Development of the vessel’s design representing a compromise between performance and construction. Further consideration will be made for reliability, maintenance, overhaul, and repair.?
• The expectations that all workstations incorporate facility fabrication capabilities, equipment, tooling, and throughput for optimum design.?
• The collaborative effort of the vessel's Build Strategy to ensure the proper breakdown of interim and all ship product families. ?
• Products should be inclusive of their work content/scope, mandatory engineering deliverables, prerequisite requirements, planning packages, and resource expectations.?
• Worker Ergonomics pertaining to the optimum installation position for production personnel to allow “down hand” installation is key in affording cost-effective production costs. Furthermore, to minimize material flow/handling costs, i.e. material wastage, fabricated part handling, and access for installation.?
• A Design ensuring ease of fabrication (minimizing cost) and installation of "Hot Work”: with outfitting “On Unit” as a primary focus. Distributive system routing locations will be planned and reviewed to allow personnel efficient installation and avoid recurring cost for temporary access.?

DFM Design Standards ?

The shipyard should establish a set of DFM Design Standards that guide each Engineering Designer to reduce cost and minimize the difficulty in constructing the vessel. ?

Typical guidelines for shipyard consideration include: ?

Standard Components:?

• Less expensive and readily available from suppliers with reduced lead times. ?
• Can be incorporated into the 3-D CAD part geometry benefiting product specification and 3-D product modeling part database catalog.?

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Engineering and Production Standards:?

• Components and their associated installation details for items such as pipe and cable hangers, penetration sleeves, ladders, manholes, and handrails.?
• Pre-approval by customer and Regulatory Agencies benefit the shipyard in repetitive DFM use by Engineering, Procurement, and Production departments. ?
• Form part of the shipyard’s 3-D product model material database and part geometry.?

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Fabrication Process Standards pertaining to typical welding and fitting joint details, pipe bending, grounding of equipment, etc. are key in selecting the optimum process for DFM cost reduction. These standards also enable the work force to be experienced and standardized on installation procedures, their QC/QA inspection, and tests requirements.?

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Reduction of the total number of parts (fabricated or purchased) is the best opportunity for reducing the shipyard’s manufacturing costs. ?

A reduction in the number of parts ensures the following:?

• Reduced Engineering development costs?
• Reduced planning and processing hours?
• Less inventory for purchased items?
• Less kitting and palletization of parts?
• Less assembly and installation timeline?
• Reduced material handling hours?
• Reduced fabrication and QC/QA hours?

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Emphasis on Modular Construction??

Modular ship construction is now common to all world-class shipyards with greater integration of design, planning, and construction utilizing 3-D CAD product modeling. To execute optimum DFM, shipyard Engineering personnel need to understand Production’s requirements to build the vessel, shipyard’s facility capabilities, fabrication equipment and tooling, the specific vessel’s Build Strategy and Work Breakdown. Computer numerical control programmable data is generated from the 3-D product model and information now feeds information directly to the shipyard’s manufacturing equipment. DFM is a collaborative effort through involvement of shipyard teams of designers, planners, and production personnel totally focused on reducing construction costs, improving productivity, repetitive best practices, and improving production schedules. ?

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The importance of Engineering designing for DFM cannot be emphasized enough for reducing total vessel costs. While Production decisions account for only 20% of the manufacturing cost, design decisions by Engineering accounts for the other 80% and include material selection, planning and process costs, and production installation costs associated with fabrication, assembly, QC/QA, Tests/Trials, etc. ?

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-GES Advisor