Chapter 7, Problem 4P

a)

Summary Introduction

To determine: The number of Kanban containers required for a container size of 100 parts.

Introduction:

Lean systems in an organization have greater impact on the customers and their values. The goal of lean thinking is to improve the productivity of the department, and the goal for any lean system is to maximize the customer value.

Explanation of Solution

Given information:

It is given that the plant would operate 2,000 hours per year, the demand rate is 100,000 units per year, and the circulation time is 24 hours.

Determine the number of Kanban containers needed for a container size of 100 parts:

It is calculated by dividing the multiple of demand and lead-time, and the container size. Standard container size is 100 parts and the demand rate is 100,000 units per year.

$\begin{array}{c}\text{Number of containers required}=\frac{DT}{C}\\ =\frac{\left(\text{Lead time}\times \text{Demand rate}\right)}{\text{Container size}}\end{array}$

Determine the lead-time (T):

It is calculated by dividing the circulation time and the operating hours per year.

$\begin{array}{c}\text{Lead-time}=\frac{\text{Circulation time}}{\text{Operating hours per year}}\\ =\frac{24}{2,000}\\ =0.012\text{ portion of a year}\end{array}$

Determine the number of standard containers needed:

It is calculated by dividing the multiple of demand and lead-time, and the container size. Standard container size is 100 parts and the demand rate is 100,000 units per year.

$\begin{array}{c}\text{Number of containers required}=\frac{\left(\text{Lead time}\times \text{Demand rate}\right)}{\text{Container size}}\\ =\frac{\left(0.012\times 100,000\right)}{100}\\ =\frac{1,200}{100}\\ =12\text{ containers}\end{array}$

Hence, the number of containers needed is 12.

b)

Summary Introduction

To determine: The effect of reducing container size from 100 parts to 60 parts.

Introduction:

Lean systems in an organization would have greater impact on the customers and their values. The goal of lean thinking is to improve the productivity of the department, and the goal for any lean system is to maximize the customer value.

Explanation of Solution

Given information:

It is given that the plant would operate 2,000 hours per year, the demand rate is 100,000 units per year, and the circulation time is 24 hours.

Determine the number of Kanban containers needed for a container size of 100 parts:

It is calculated by dividing the multiple of demand and lead-time, and the container size. Standard container size is 60 parts and the demand rate is 100,000 units per year.

$\begin{array}{c}\text{Number of containers required}=\frac{DT}{C}\\ =\frac{\left(\text{Lead time}\times \text{Demand rate}\right)}{\text{Container size}}\end{array}$

Determine the lead-time (T):

It is calculated by dividing circulation time and the operating hours per year.

$\begin{array}{c}\text{Lead-time}=\frac{\text{Circulation time}}{\text{Operating hours per year}}\\ =\frac{24}{2,000}\\ =0.012\text{ portion of a year}\end{array}$

Determine the number of standard containers needed:

It is calculated by dividing the multiple of demand and lead-time, and the container size. Standard container size is 60 parts and the demand rate is 100,000 units per year.

$\begin{array}{c}\text{Number of containers required}=\frac{\left(\text{Lead time}\times \text{Demand rate}\right)}{\text{Container size}}\\ =\frac{\left(0.012\times 100,000\right)}{60}\\ =\frac{1,200}{60}\\ =20\text{ containers}\end{array}$

Hence, the number of containers needed is 20.

c)

Summary Introduction

To determine: Process takt time.

Introduction:

Lean systems in an organization would have greater impact on the customers and their values. The goal of lean thinking is to improve the productivity of the department, and the goal for any lean system is to maximize the customer value.

Explanation of Solution

Given information:

It is given that the plant would operate 2,000 hours per year, the demand rate is 100,000 units per year, and the circulation time is 24 hours.

Determine the process takt time:

It can be calculated by multiplying the minutes per hour with the operating time per hour and dividing it by the demand rate (D).

$\begin{array}{c}\text{Process takt time}=\frac{\left(\text{Minutes per hour}\times \text{Operating time per hour}\right)}{\text{Demand rate}}\\ =\frac{\left(60\text{minutes}\times \text{2,000}\right)}{100,000\text{ units}}\\ =1.2\text{ minutes per unit or 72 seconds}\end{array}$

Hence, the process takt time is 1.2 minutes or 72 seconds.

c)

Summary Introduction

To determine: Process takt time if the demand is 80,000 units.

Introduction:

Lean systems in an organization would have greater impact on the customers and their values. The goal of lean thinking is to improve the productivity of the department, and the goal for any lean system is to maximize the customer value.

Explanation of Solution

Given information:

It is given that the plant would operate 2,000 hours per year, the demand rate is 80,000 units per year, and the circulation time is 24 hours.

Determine the process takt time:

It can be calculated by multiplying the minutes per hour with the operating time per hour and dividing it by the demand rate (D).

$\begin{array}{c}\text{Process takt time}=\frac{\left(\text{Minutes per hour}\times \text{Operating time per hour}\right)}{\text{Demand rate}}\\ =\frac{\left(60\text{minutes}\times \text{2,000}\right)}{80,000\text{ units}}\\ =1.5\text{ minutes per unit or 90 seconds}\end{array}$

Hence, the process takt time is 1.5 minutes or 90 seconds.