Chapter 3, Problem 5PA

a)

Summary Introduction

To draw: A process flow diagram for this process.

Explanation of Solution

Given information:

Process flow diagram:

b)

Summary Introduction

To determine: The capacity at the resource “Dentist”.

Explanation of Solution

Given information:

Calculation of capacity:

Formula:

The capacity at “Dentist” is 20 patients.

c)

Summary Introduction

To determine: The bottleneck in the process.

Explanation of Solution

Given information:

Determination of bottleneck:

The resource with the lowest capacity is the bottleneck. The resource “Dental assistant” has the lowest capacity of 12 patients per hour.

Hence, the bottleneck is Dental assistant.

d)

Summary Introduction

To determine: The flow rate.

Explanation of Solution

Given information:

Determination of flow rate:

The bottleneck flow rate determines the flow rate of the process. Therefore, the flow rate of the dentist is:

$\begin{array}{c}\text{Flow rate}=\text{Number of workers}\times \frac{\text{Minutes per hour}}{\text{Minutes per patient}}\\ =3\times \frac{60}{15}\\ =12\text{ patients}\end{array}$

The flow rate is 12 patients per hour.

e)

Summary Introduction

To determine: The utilization of resource “Receptionists”.

Explanation of Solution

Given information:

Calculation of utilization:

$\begin{array}{c}\text{Utilization}=\frac{\text{Flow rate}}{\text{Capacity}}\times 100\\ =\frac{12}{24}\times 100\\ =\frac{1}{2}\times 100\\ =50\%\end{array}$

The utilization is 50%.

f)

Summary Introduction

To determine: The cycle time of the process.

Explanation of Solution

Given information:

Calculation of cycle time:

The demand is constrained and has a flow rate of

$\begin{array}{c}\text{Cycle time}=\text{Total processing time+}\left[\left(\text{Number of patients-1}\right)\times \text{Cycle time}\right]\\ \text{=55+}\left[\left(15-1\right)\times \frac{\text{Minutes per hour}}{\text{Flow rate}}\right]\\ =\text{55+}\left[14\times \frac{\text{60}}{\text{12}}\right]\\ =55+70\\ =125\text{ minutes}\end{array}$

The cycle time is 125 minutes.

g)

Summary Introduction

To determine: The cycle time of the process.

Explanation of Solution

Given information:

Calculation of cycle time:

$\begin{array}{c}\text{Cycle time}=\text{Total processing time+}\left[\left(\text{Number of patients-1}\right)\times \text{Cycle time}\right]\\ \text{=55+}\left[\left(11-1\right)\times \frac{\text{Minutes per hour}}{\text{Flow rate}}\right]\\ =\text{55+}\left[10\times \frac{\text{60}}{\text{12}}\right]\\ =55+50\\ =105\text{ minutes}\end{array}$

The cycle time is 105 minutes.

h)

Summary Introduction

To determine: The time taken to serve 20 patients

Explanation of Solution

Given information:

Calculation of time taken to serve 20 patients:

There are 3 resources and the cycle time is 5 minutes.

$\begin{array}{c}\text{Time taken}=\left(3\times 5\right)+\left[\left(20-1\right)\times 5\right]\\ =15+\left(19\times 5\right)\\ =15+95\\ =110\text{ minutes}\end{array}$

The time taken to serve 20 patients is 110 minutes.