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FUNDAMENTALS OF PRODUCTION-PROCESS DESIGN The designs of the product and of the production process are carefully worked out b efore s tarting large - s eries or mass production. The extensive 1 a n n i n g. Production planning comprises a whole range of measures undertaken at definite dates and includes the following five basic stage s : 1 . Desi gn o f the n e w products , o r radical modification o f an existing design (improvements ). 2 . Preparation and testing of experimental prototypes . 3 . Planning the production process , and the equipment and tooling. 4 . Manufacture of the production e quipment. 5 . Testing and development o f the p roduction process o n a pilot batch. In the watch industry, the design of new products o r the radical modifi- cation of exis ting designs is c onducted in the following stage s : Establishing the p roduct s pecifications: Working out the design d rawings . Working out technical specifications for the parts and s ubass emblies . Preparing design drawings of gear profiles and special profiled parts . E s tablishing the assembly p rocedures for the product. The experimental p rototypes are made in the experimental s hop of the plant under the s upervis ion of the s enior designer . The drawings are cor rected in the cpurs e of prototype manufacture , and the dimensions and tolerances are carefully c oordinated. Prototypes are thoroughly tested in the watch laboratory in order to ascertain whether the design meets the specifications . Process planning c onsists in establishing the s equence of operations for each part and for assembly operations , s electing the equipment, machinery and tools, establishing the p rocess c onditions , calculating the time rates for the operations , and establis hing the work category. In working out the proces ses the rates of material consumption are cal culated, the dimensions and s hape of the parts at each operation are fixed, and the m eans and methods of inspection are established. All the s e data are noted on engineering charts of different shapes and purpose s , whos e extent and contents depend on the type of production. The most c omplicated among the operations are tested experimentally in ihe c ourse of the p rocess planning. The production equipme nt is built by the plant's tool s hop and the techno logical process planned is us ually tested on a pilot batch. The pilot batch is m achined and assembled in the bas ic shops on machin e ry and at workplaces identical with those planned for the actual production The punching dies , fixtures and other pieces of equipment are tested , and corrections are introduced into the engineering charts and the equipment drawings if necessary . After the process has b een tested, normal production begins . The test ing of the planned process by m eans of a pilot batch is a necessary stage for mass and large - s eries production. In order to s horten the time taken by p roduction planning, many j obs are conducted in parallel by the chief production engineer ' s and the chief de 3 3 |