41 Defense AT&L: November-December 2004

Watts is a technical team leader in the Production Engineering Division, Engineering Directorate, U.S. Army Research, Development, and EngineeringCommand, Redstone Arsenal, Huntsville, Ala. He holds a bachelor’s degree in aerospace engineering from the Georgia Institute of Technology.

B E S T P R A C T I C E S

Using Design for Manufacture And Assembly

To Meet Advanced Precision KillWeapon System Cost Goals

Steve Watts

In our environment of state-of-the-artweapon systems development, the em-phasis is largely on ensuring technologi-cal feasibility to meet performance re-quirements. However, for overall program

success, the manufacturing processes andcosts associated with the design must also beaddressed. Numerous studies show that themost effective time to implement cost-sav-ing changes is early in the product designcycle. One way to achieve this is to ensurethat design engineers and manufacturing en-gineers work concurrently to develop the de-sign. The Advanced Precision Kill WeaponSystem (APKWS) Program has created theopportunity for this type of environmentthrough the implementation of design formanufacture and assembly (DFMA) work-shops during the system development anddemonstration (SDD) phase.

The Genesis of APKWSThe Army has identified a requirement for alow-cost precision weapon system to fill thecritical weapon system gap between the cur-rent aimed Hydra-70 rocket system and theHELLFIRE anti-armor missile. Our nation’smilitary strategy requires systems that aremore precise, lighter, more deployable, andthat produce higher ratios of kills per plat-form. The future projected military cam-paigns will be characterized by military op-erations in urban terrain, a proliferation ofsoft to lightly armored targets, fighting inclose proximity to noncombatants, and ahigh potential for collateral damage.

In February 2003, the Aviation Rocketsand Missiles Project Office of the Tactical

Missiles Program Executive Office, Redstone

Arsenal, Ala., awarded General Dynamics Armament andTechnical Products a 30-month (incentivized to 25-month)SDD contract to develop the APKWS. General Dynamicshas contracted with BAE Systems, Nashua, N.H., to de-velop a newly designed guidance section that integrateswith the existing Hydra-70 components and launch equip-ment. Using a semi-active laser-guided seeker, the APKWSwill be a highly accurate weapon that complements theHELLFIRE missile in a precision strike by offering a lower-cost alternative against soft-point targets, while mini-mizing collateral damage. This system will provide im-proved accuracy over the current Hydra-70 munitionsused on the AH-64 Apache, the OH-58 Kiowa Warrior, aswell as various other rotary and fixed-wing aircraft plat-forms. The APKWS fully embodies the Army’s vision fora lighter, versatile, and decisively lethal force.

In September 2002 (five months prior to SDD award), theArmy conducted an independent engineering and man-ufacturing readiness level (EMRL) review of the advancedtechnology demonstration (ATD) phase design of theAPKWS. There is an ongoing effort by the Missile DefenseAgency (MDA) and Future Combat Systems (FCS) to es-tablish EMRLs to assess the manufacturing process ma-turity of a design—similar to the way the technology readi-ness levels address the technology maturity of a design.The review of APKWS was conducted by the productionengineering division of the Aviation and Missile Research,Development, and Engineering Center at the U.S. ArmyResearch, Development, and Engineering Command,Redstone Arsenal, Ala. It represents the first applicationto a major Army missile system. The purpose of the re-view was to assess the maturity of the manufacturingprocesses and materials associated with the design, iden-tify producibility issues early, and assess the program’sreadiness to transition into SDD.

The conclusion from the EMRL review was that all themanufacturing processes and materials associated withthe APKWS design were relatively mature, and no is-sues would preclude this program from transitioninginto SDD. However, given the schedule constraints in

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SDD and the average unit production cost goals, pro-ducibility emphasis would need to be placed on severalassemblies in order to meet rate requirements. Themost significant concern was with the seeker optics as-sembly. The design was very complex, consisted of nu-merous parts, required substantial manual assembly byskilled optics technicians, and was not readily conduciveto automated assembly processes. In addition, therewere concerns with critical characteristics that madethe design difficult and costly to manufacture and proneto breakage in handling and assembly of the optic fibers.The control actuation system also presented pro-ducibility concerns because it, too, consisted of nu-merous parts and required extensive manual assembly.Many of the parts were very intricate, requiring tediousassembly processes, and included an area that requiredmatch-drilling operations between two parts. The rec-ommendation from the EMRL review was that severalassemblies needed to undergo an extensive DFMAprocess to reduce the number of parts associated withthe designs and to generate ideas that would make thedesigns more cost effective to manufacture.

The APKWS program has an aggressive 30-month SDDphase and challenging cost targets for the production unitprice. These factors drive the need for innovative ap-proaches during the SDD phase like DFMA workshopsand other concurrent engineering techniques to quicklyand efficiently focus the development team on meetingthe schedule and cost targets.

DFMA: Principles and BenefitsDFMA is a process where a cross-functional team con-currently and proactively evaluates a design early in thedevelopment process. As a result, attention is given to themanufacturing process associated with a design, and po-tential manufacturing problems can be averted, therebyreducing manufacturing costs. It also promotes team buy-in and increases organizational ownership. The benefitsinclude a simplified design with reduced cycle times andengineering changes, resulting in a reduced life cycle costwith improved quality.

A major benefit of DFMA is that it enables product de-sign engineers and manufacturing design personnel tocome together and brainstorm the design. The best re-sults are realized when there is a structured approach tothese workshops and an independent party facilitates theDFMA process. General Dynamics and BAE Systems se-lected Boothroyd Dewhurst Inc. to facilitate their DFMAworkshops. Boothroyd Dewhurst, regarded as one of thepioneering companies in the area of DFMA, provides ini-tial training on DFMA and has developed several softwaretools that provide structure to the brainstorming activityand assist in the step-by-step evaluation of the design.

Boothroyd Dewhurst’s DFMA® software provides a met-ric tool for analyzing and evaluating product designs forease of assembly and manufacturing efficiency at the ear-

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liest stages of design. The early and accurate cost un-derstanding provided by DFMA enables product devel-opment teams to manage product cost and consider al-ternative designs. The software is based on twointerlocking approaches: design for assembly (DFA) anddesign for manufacture (DFM).

The DFA software guides engineers to evaluate the func-tional purposes of each component in the design of a totalproduct. Data accumulate as the engineers question therelationships between items in the design according tothe DFA methodology. DFA software also enables the de-signers to rate each component on its ease of orientationand assembly. The DFA software-generated data guidethe design teams to focus on part count to achieve costreduction through product simplification.

Advanced Precision Kill Weapon System

fired from Apache helicopter.

Artist’s rendition courtesy of BAE Systems, Nashua, N.H.

Boothroyd Dewhurst’s DFM Concurrent Costing® soft-ware identifies the major cost drivers associated withmanufacturing and finishing parts; it helps engineerschoose the most cost-effective shape-forming process fora part and consider how individual part features mightbe modified to optimize manufacturing costs. The soft-ware contains an extensive library of data for varied ma-terials, operations, and processes. A key benefit of DFMsoftware is that in just a few simple steps, it quickly gen-erates an initial cost estimate at any stage of design.

Longbow HELLFIRE Proves Value of DFMA The Aviation Rockets and Missiles Project Office and BAESystems have already experienced the benefits of a suc-cessful DFMA exercise on the Longbow HELLFIRE sys-tem. In the early 1990s, the program was experiencingdifficulty in developing a receiver design that could betransitioned to rate production. In March 1995, the primecontractor, Lockheed Martin, facilitated a DFMA at BAESystems as part of a cost reduction program. The DFMAmethodologies and lean manufacturing activities havecontributed significant cost reductions to the program.These initiatives have resulted in reduced parts count, in-creased test yields, reduced hours per unit by 20 percent,reduced number of operations by 20 percent, reducedlayout square footage by 20 percent, and increased pro-duction output from 52 units per month to 220 units permonth. The Longbow HELLFIRE program has now de-livered over 10,000 receivers. The combination of theseenhancements has established the program as a cost-ef-fective solution for continued multi-year deployment.

Applying DFMA to APKWSThe APKWS team (the Army, General Dynamics, and BAESystems) decided on a course of action for DFMA imple-mentation on the guidance section and its major sub-assemblies, including individual workshops held at thesource of the major subassembly or system. A cross-func-tional team of program managers, design engineers, pro-ducibility engineers, manufacturing engineers, design tocost engineers, and assembly technicians was established.Gerry Burke of J&J Engineering facilitated the workshopsusing the Boothroyd Dewhurst DFMA software.

Key to the success of the workshop is doing the requiredpre-work to establish a baseline: establishing a level break-down, developing a product structure including detailedparts lists and data, and generating a complete assem-bly process. Loading these data into the tool prior to theworkshop saves valuable time and accelerates the learn-ing process. The software assigns assembly standardsand tooling costs to the individual parts and operationsby considering commodity, size, and complexity. Theteam then reviews the baseline data to find opportunitiesfor part reductions and assembly simplifications. The nextstep is to agree on the ideas and perform a re-designanalysis to determine potential cost savings and quality

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improvements. A concurrent cost model is then estab-lished for both the original and proposed re-designs toidentify potential savings. The team agrees on a list of ac-tion items to incorporate the ideas developed during theworkshop.

This process was instrumental in identifying significantcost reduction opportunities on the control actuator sys-tem and the guidance section of APKWS. Several otherworkshops are planned, and action item closure is beingmonitored to capture real savings.

DFMA parameters were also used to address producibil-ity concerns on the seeker optics assembly. The teambrainstormed alternative designs and fabrication tech-nologies to aggressively reduce the number of separatepiece parts in the seeker optics assembly. Fasteners wereeliminated. Some parts were redesigned so they wouldbe symmetrical and easier to install. Parts were also de-signed to be self-aligning, further reducing the complex-ity of the assembly process.

Early Results Show PromiseWhile the final results of the DFMA activities on theAPKWS will not be fully realized until rate production isachieved several years down the road, the program hasalready generated several tangible and intangible bene-fits. The tangible benefits are the incorporation of signif-icant simplifications to the preliminary design: things suchas elimination of fasteners, overall parts count reductions,redesigns for ease of assembly, and self-alignment fea-tures. In addition, numerous ideas are still being evalu-ated. The intangible benefits have been the establishmentof a true concurrent engineering environment for thisprogram that has resulted in overall team buy-in and own-ership and improved communication. While the programis still in the early stages of final development and sev-eral challenges remain, the DFMA activities incorporatedby the APKWS team have built a strong framework to es-tablish producibility as a priority, overcome upcomingchallenges, and eventually achieve overall schedule andcost goals.

Editor’s note: The author welcomes comments andquestions and can be contacted at charles.s.watts@us.army.mil.

The author acknowledges contributions from Fritz Gor-don of the Aviation, Rockets, and Missile Project Office;Ron Payson and Steve Griffiths of General DynamicsArmament and Technical Products; Kim Cadorette andJoe Tiano of BAE Systems; and Nick Dewhurst and JohnGilligan of Boothroyd Dewhurst Inc. For further infor-mation on APKWS, contact Carol Frazier, project man-ager, aviation rockets and missiles, carol.frazier@msl.redstone.army.mil.