Acertain job shop specializes in one-of-a-kind orders dealing with parts of medium-to-high complexity. a typical part is processed sequentially through 10 machines in batch sizes of one. the shop contains a total of eight conventional machine tools and operates 35 hours per week of production time. the machine tools are interchangeable in the sense that they can be set up for any operation required on any of the parts. average time values on the part are: machining time per machine = 0.5 hour, work handling time per machine = 0.3 hour, tool change time per machine = 0.2 hours, setup time per machine = 6 hours, and non-operation time per machine = 12 hours. a new programmable machine has been purchased by the shop that is capable of performing all ten operations in a single setup. the programming of the machine for this part will require 20 hours; however, the programming can be done offline, without tying up the machine. the setup time will be 10 hours. the total machining time will be reduced to 80% of its previous value due to advanced tool control algorithms; the work handling time will be the same as for one machine; and the total tool change time will be reduced by 50% because it will be accomplished automatically under program control. for the one machine, non-operation time is expected to be 12 hours.
explain how the variables used in the equations are found.
(a) determine the manufacturing lead time for the traditional method and for the new method.
(b) compute the plant capacity for the following alternatives: (i) a job shop containing the eight traditional machines and (ii) a job shop containing two of the new programmable machines. assume the typical jobs are represented by the data given above.
(c) determine the average level of work-in-process for the two alternatives in part (b), if the alternative shops operate at full capacity.