July/August_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | J U L Y / A U G U S T 2 0 2 0 2 7 months before that milestone. If suc- cessful, the pre-program continues to the second milestone, the official start of the program and its inclusion in the product cycle plan. From the development phase on- ward, programs follow a strictly defined timeline with multiple teams working in parallel. Intermediary milestone re- views confirm the program strategy and the compatibility of various targets. The development phase ends with program approval by the board and disburse- ment of the financial resources required to bring it to production, to the tune of hundreds of millions for large and com- plex programs. The final engineering re- view takes place a few weeks later. It is “pencil down” for engineering, with no further engineering changes allowed unless required to pass durability tests or regulations. Manufacture of the tooling for pro- duction takes place during the execu- tion phase, which includes two addi- tional milestones—one for the verifica- tion prototypes (VP) build, followed by a management review after two succes- sive tuning loops to resolve any defi- ciencies identified by VP testing. The launch phase follows, with a series of builds to test and tune the pro- duction system. From the second build on, units are now officially preproduc- tion units, technically indistinguishable from units salable to the public. Pro- duction starts after a final review and usually includes a public celebration. A body shop is designed for the 20-25 years of a platform’s life and the initial investment can easily exceed $250 million. Covering several acres, these shops are highly efficient produc- tion lines equipped with three types of stations. First, base stations are set up, which will remain compatible with the various models throughout the life of the platform, with minimal modifica- tions. Specialized stations are the sec- ond type, which are dedicated to a particular model and cannot be adapt- ed without a production interruption. Finally, flexible stations are sprinkled throughout the lines, which are either idle or serve as make-up stations during downtime at other stations. During a model changeover, these reserve sta- tions receive tooling for the newmodel. As the start of production approaches, the lines switch from the outgoing mod- el to the new model in a ramp-down/ ramp-up switchover to enable tuning and debugging of the new tooling. Af- ter the new model is in full production, stations dedicated to the previous mod- el are stripped of their tooling and be- come the new flexible stations, ready for the next model changeover. RETOOLING FOR ALUMINUM Switching to an aluminum con- struction meant new tooling for ev- ery station, invalidating the traditional changeover approach. Previous stud- ies had explored multiple approach- es to retool and reuse, but in the end had only confirmed the necessity for a new body shop. The Jaguar XJ was a low-volume luxury product, with a small size and slow body shop that had offered considerable flexibility for the changeover. For D11, Ford was looking to deliver a full-size body shop working at the fastest possible cycle time. The first question was how to best accom- plish the transition from a steel body shop. The second question was wheth- er the joining technology had matured enough to support the required rates and productivity without an extended ramp-up. It was a complex assignment and the engineers spent several months assessing the state of the art and sort- ing through various scenarios. The sale of JLR occurred at the project’s mid- point, highlighting the sense of poten- tial loss of expertise. On June 30, 2008, Tesla an- nounced a fully electric, five-passen- ger sports sedan dubbed the Model S, which would sell for $60,000 and offer 225 miles on a full charge. The carmak- er said it would produce the vehicles in a brand new manufacturing plant in Northern California, according to an ar- ticle on Engadget.com at the time. Not mentioned in the press release was the fact that the car was an aluminum- intensive structure. The end of the D11 study coin- cided with the release of Ford’s sec- ond quarter results, which showed an $8.7 billion quarterly loss, the largest in its 105-year history. As gas prices hov- ered around $3 per gallon, Ford an- nounced an aggressive plan to switch production to small fuel-efficient cars. Clearly, the company could not afford a new plant or the conversion of a plant scheduled to close. The final straw was that the manufacturing team estimat- ed a six to nine month changeover for a “tear down and rebuild” of the body shop at a time when the company could least afford it. On the stamping side, the engineers had acknowledged that they were not yet ready for launching an aluminum project of that magnitude. However, there were a couple of posi- tive outcomes. On the planning front, the project secured small but import- ant timing adjustments to Ford’s glob- al product development system. On the production side, the stamping pro- ductivity studies had cataloged a wide range of performance but had clearly demonstrated that on modern stamp- ing lines, aluminum parts ran with a productivity equal to steel. These two findings removed major planning and financial uncertainties, helping to move the next aluminum-intensive vehicle (AIV) study closer to success. A standard methodology and a library of informa- tion were two other outcomes of the D11 study that would greatly simplify future AIV studies. Ford assembly line, circa 2008. Courtesy of Ford Motor Company.