Q$7\mathrm{.}1*($Window Boxes$)$ Metal window boxes are manufactured in two process steps: stamping

and assembly. Each window box is made up of three pieces: a base $($one part A$)$ and two

sides $($two part Bs$).$

The parts are fabricated by a single stamping machine that requires a setup time of

$120$ minutes whenever switching between the two part types. Once the machine is set up$,$

the processing time for each part A is one minute while the processing time for each part

B is only $30$ seconds.

Currently, the stamping machine rotates its production between one batch of $360$ for

part A and one batch of $720$ for part B$.$ Completed parts move from the stamping machine

to the assembly only after the entire batch is complete.

At assembly, parts are assembled manually to form the finished product. One base

$($part A$)$ and two sides $($two part Bs$),$ as well as a number of small purchased components,

are required for each unit of final product. Each product requires $27$ minutes of labor time

Higher

Frontier

Now

Setup Occurs

at Bottleneck

$=>$ Use Larger

Batches

Reduce

Setup Times

Setup Occurs at

Nonbottleneck

$=>$ Use Smaller Batches

Lower Per$-$ Costs

Unit Costs

High Per$-$

Unit Costs

Low

High

Responsiveness

FIGURE $7\mathrm{.}12$

Choosing a Batch

Size

$7\mathrm{.}10$

Further

Reading

$7\mathrm{.}11$

Practice

Problems

$(*$ indicates that the solution is at the end of the book$)$

cac$25200\_$ch$07\_114-143.$indd $1371/10/126$:$18$ PM

Rev. Confirming Pages

$138$ Chapter $7$

to assemble. There are currently $12$ workers in assembly. There is sufficient demand to sell

every box the system can make.

a$.$ What is the capacity of the stamping machine?