An IE with consultation with operation workers has established a safe, effective and efficient job method for the "front wheel $-$ spokes $-$tire" sub$-$assembly of a junior boy's bicycle using principles of motion economy. Further the lE$,$ using principles of "stop$-$watch time systems $($SWTS$)"$ has to develop a "standard time" and "standard cost of labour" for the production of this sub$-$ assembly.

$($a$)$ Enumerate and clearly state the principles of motion economy.

$($b$)$ Each job cycle of the established method for assembly of this front wheel sub$-$assembly produces $2$ units per cycle. The method involves wel designed jigs and fixtures, manual human assembly work and machine controlled work. Average measured real time of manual assembly is $1\mathrm{.}38$ minutes per job cycle. Machine time per work cycle si $0\mathrm{.}43$ minutes per cycle. Allowances are $16$ percent for the human assembly work portion and $10$ percent for the machine portion. Performance rating $=1\mathrm{.}10$ percent for this operation. Given that direct labour wage rate si $$17\mathrm{.}25$ per hour, establish the standard time and standard cost per $100$ units of this "front wheel $-$spokes$\_$tire" sub$-$assembly.