A job shop has four work centers: A$,$ B$,$ C$,$ and D that are currently located in a facility as in

locations $1,2,3,$ and $4$ as shown:

A in $1$ B in $2$ C in $3$

D in $4$

The distance in meters between each pair of locations are as follows:

$1234$

$1408070$

$24030$

$370$

$4$

The loads moved between each pair of work centers per week are as follows:

A B C D

A $150300160$

B $12090$

C $50$

D $$

Material handling cost is $$2$ per load per meter.

a$.$ What is the total material handling cost per week for the current layout?

b$.$ Propose a revised $($best$)$ layout by switching the locations of some centers. What would be the

total materials handling cost for this revised layout?