Compute Lead Time

Isaacson Dental Inc. is considering a new lean product cell. The present manufacturing approach produces a product in four separate steps. The production batch sizes are $50$ units. The process time for each step is as follows:

$\backslash$table$[[$Process Step $1,6$ minutes$],[$Process Step $2,12$ minutes$],[$Process Step $3,9$ minutes$],[$Process Step $4,3$ minutes$]]$

The time required to move each batch between steps is $6$ minutes. In addition, the time to move raw materials to Process Step $1$ is also $6$ minutes, and the time to move completed units from Process Step $4$ to finished goods inventory is $6$ minutes.

The new lean layout will allow the company to reduce the batch sizes from $50$ units to $2$ units. The time required to move each batch between steps and the inventory locations will be reduced to $1$ minute. The processing time in each step will stay the same.

Determine the value$-$added, non$-$value$-$added, and total lead times, and the value$-$added ratio under the $($a$)$ present and $($b$)$ proposed production approaches. If required, round percentages to one decimal place.

$\backslash$table$[[,$Present Approach,Proposed Approach$],[$Value$-$added time,min,min$],[$Non$-$value$-$added time,min,min$],[$Total lead time,min,min$],[$Value$-$added ratio $($as a percent$),\%,\%$