Calculate Lead Time

Williams Optical Inc. is considering a new lean product cell. The present manufacturing approach produces a product in four separate steps. The production batch sizes are $53$ units. The process time for each step is as follows:

Process Step $17$ minutes

Process Step $25$ minutes

Process Step $39$ minutes

Process Step $44$ minutes

The time required to move each batch between steps is $10$ minutes. In addition, the time to move raw materials to Process Step $1$ is also $10$ minutes, and the time to move completed units from Process Step $4$ to finished goods inventory is $10$ minutes.

The new lean layout will allow the company to reduce the batch sizes from $53$ units to $3$ units. The time required to move each batch between steps and the inventory locations will be reduced to $2$ minutes. 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 present and proposed production approaches. If required, round percentages to one decimal place.

Present Approach Proposed Approach

Value$-$added time

fill in the blank $1$

min

fill in the blank $2$

min

Non$-$value$-$added time

fill in the blank $3$

min

fill in the blank $4$

min

Total lead time

fill in the blank $5$

min

fill in the blank $6$

min

Value$-$added ratio $($as a percent$)$

fill in the blank $7$

$\%$

fill in the blank $8$

$\%$