Question 1

The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time and predecessor as shown in the table. They work a 7 hour day and want to produce at a rate of 360 units per day. What should their takt time be? $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 40 & \text { A } \
\hline \text { D } & 55 & \text { B, C } \
\hline \text { E } & 40 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { F, G } \
\hline
\end{array}$$

Accepted Answer

Takt time is the available production time divided by the demand rate. In this case, the available production time is 7 hours per day, or 25,200 seconds per day. The demand rate is 360 units per day. Therefore, the takt time is 25,200 seconds per day / 360 units per day = 70 seconds per unit.

Question 2

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. Without using more than one worker per station, what is the maximum output achievable in the 7.5 hour work day?

Accepted Answer

First, calculate the takt time: $7.5 \text{ hours} \times 3600 \text{ sec/hour} = 27000 \text{ sec/day} \div 400 \text{ units} = 67.5 \text{ sec/unit}$. Then, assign tasks to workstations to not exceed this takt time, considering task times and predecessors. The output is limited by the total available time and takt time, not reaching the options A, B, or C, making D the closest realistic output given the constraints.

Question 3

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. What is the takt time?

Accepted Answer

To calculate the takt time, we need to divide the total available time by the desired production rate. Total available time can be calculated by multiplying the number of productive hours by 3600. 
Total available time = 7.5 x 3600 = 27,000 seconds 
Desired production rate = 400 units 
Takt time = Total available time/Desired production rate 
Takt time = 27,000/400 = 67.5 seconds.

Now, we need to assign tasks to workstations to fill up as much takt time as possible. We start by finding the longest task, which is task F with a duration of 65 seconds. We assign task F to workstation 1. 
Task F = 65 seconds -> Workstation 1 
Task D = 55 seconds -> Workstation 2 
Task B = 50 seconds -> Workstation 3 
Task A = 45 seconds -> Workstation 4 
Task H = 35 seconds -> Workstation 5 
Task C = 20 seconds -> Workstation 6 
Task E = 15 seconds -> Workstation 7 
Task G = 25 seconds -> Workstation 8

By assigning tasks in this manner, we have ensured that each workstation is busy for at least 67.5 seconds, which is the takt time.

Question 4

Name a service business that relies heavily on intangible activities. How does the level of intangibility fit with the degrees of contact and customization?

Accepted Answer

The answer of Name a service business that relies heavily...

Question 5

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. The process design team realizes that the potential spike in demand for this device requires increased output. They elect to add a seventh worker to their production team at the first station. What is the net effect of adding this worker?

Accepted Answer

The answer of Use this scenario for the following question(s).
The...

Question 6

The table depicts a production line that has been balanced with a takt time of 2 minutes. What is the efficiency of this balance? $$\begin{array} { | l | c | c | c | c | c | c | } 
\hline \text { Workstation } & 1 & 2 & 3 & 4 & 5 & 6 \
\hline \text { Task } & \mathrm { A } , \mathrm { B } & \mathrm { C } & \mathrm { D } , \mathrm { E } , \mathrm { F } & \mathrm { G } , \mathrm { H } & \mathrm { I } & \mathrm { J } , \mathrm { K } , \mathrm { L } \
\hline \text { Time } ( \mathrm { min } ) & 1,1 & 1.8 & 1,0.5,0.4 & 0.9,0.8 & 1.8 & 0.5,0.5,0.6 \
\hline
\end{array}$$

Accepted Answer

The answer of The table depicts a production line that...

Question 7

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 8 productive hours available in a day and the manufacturer wishes to produce 400 units. Use this information to answer the following question(s).
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \mathrm { J } & 45 & \cdots \
\hline \text { K } & 50 & \mathrm {~J} \
\hline \mathrm { L } & 40 & \mathrm {~J} \
\hline \mathrm { M } & 55 & \mathrm {~K} , \mathrm {~L} \
\hline \mathrm { N } & 40 & \mathrm { M } \
\hline \mathrm { O } & 65 & \mathrm { M } \
\hline \text { P } & 25 & \mathrm {~N} \
\hline \text { R } & 35 & \mathrm { O } , \mathrm { P } \
\hline
\end{array}$$
-Refer to the scenario above. What is the theoretical minimum number of stations?

Accepted Answer

The theoretical minimum number of stations can be found using the longest sequence of dependent tasks, which in this case is J-K-M-N-P-R. There are six tasks in this sequence, so the theoretical minimum number of stations is six. However, since task M has two predecessors (K and L), it would be more efficient to split task M into two parallel stations, which would bring the total number of stations to five.

Question 8

Name two restaurants that score differently on at least two scales in the service positioning space and provide examples of how they differ.

Accepted Answer

The answer of Name two restaurants that score differently on...

Question 9

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 8 productive hours available in a day and the manufacturer wishes to produce 400 units. Use this information to answer the following question(s).
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \mathrm { J } & 45 & \cdots \
\hline \text { K } & 50 & \mathrm {~J} \
\hline \mathrm { L } & 40 & \mathrm {~J} \
\hline \mathrm { M } & 55 & \mathrm {~K} , \mathrm {~L} \
\hline \mathrm { N } & 40 & \mathrm { M } \
\hline \mathrm { O } & 65 & \mathrm { M } \
\hline \text { P } & 25 & \mathrm {~N} \
\hline \text { R } & 35 & \mathrm { O } , \mathrm { P } \
\hline
\end{array}$$
-Refer to the scenario above. The manager assigns tasks to workstations and breaks ties using a longest operation heuristic. That is, if two or three tasks could be assigned to a given station, the manager assigns the longest task first and then fills in the remaining time at the workstation as completely as possible. Using this approach, what task(s)would be assigned at the fourth station?

Accepted Answer

The longest task that can be assigned to the fourth station is M, which has a time of 55 seconds.

Question 10

The table depicts a production line that has been balanced with a takt time of 2 minutes. What is the percent idle time of this balance? $$\begin{array} { | l | c | c | c | c | c | c | } 
\hline \text { Workstation } & 1 & 2 & 3 & 4 & 5 & 6 \
\hline \text { Task } & \mathrm { A } , \mathrm { B } & \mathrm { C } & \mathrm { D } , \mathrm { E } , \mathrm { F } & \mathrm { G } , \mathrm { H } & \mathrm { I } & \mathrm { J } , \mathrm { K } , \mathrm { L } \
\hline \text { Time } ( \mathrm { min } ) & 1,1 & 1.8 & 1,0.5,0.4 & 0.9,0.8 & 1.8 & 0.5,0.5,0.6 \
\hline
\end{array}$$

Accepted Answer

To calculate the percent idle time, we need to first calculate the cycle time of the production line, which is the sum of the task times for all workstations. 
Cycle time = 1 + 1 + 1.8 + 1 + 0.9 + 0.8 + 1.8 + 0.5 + 0.5 + 0.6 = 9.9 minutes 
 
The percent idle time can then be calculated as: 
Percent idle time = (cycle time - total work time) / cycle time x 100% 
 
Total work time = sum of all task times 
Total work time = 1 + 1 + 1.8 + 1 + 0.9 + 0.8 + 1.8 + 0.5 + 0.5 + 0.6 = 9.9 minutes 
 
Percent idle time = (9.9 - 2) / 9.9 x 100% 
Percent idle time = 78.78% 
 
Therefore, the percent idle time of this balance is 10%.

Question 11

The table depicts an production line that has been balanced with a takt time of 2 minutes. Where would you add a worker if you wanted to increase the output rate while keeping six work stations? $$\begin{array} { | l | c | c | c | c | c | c | } 
\hline \text { Workstation } & 1 & 2 & 3 & 4 & 5 & 6 \
\hline \text { Task } & \mathrm { A } , \mathrm { B } & \mathrm { C } & \mathrm { D } , \mathrm { E } , \mathrm { F } & \mathrm { G } , \mathrm { H } & \mathrm { I } & \mathrm { J } , \mathrm { K } , \mathrm { L } \
\hline \text { Time } ( \mathrm { min } ) & 1,1 & 1.8 & 1,0.5,0.4 & 0.9,0.8 & 1.8 & 0.5,0.5,0.6 \
\hline
\end{array}$$

Accepted Answer

The answer of The table depicts an production line that...

Question 12

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. What task(s)should be assigned at the third workstation?

Accepted Answer

To balance the line, we need to calculate the takt time, which is the available production time divided by the required production rate. The required production rate is 400 units per day, or 28.8 units per hour (400/7.5).

Next, we need to assign tasks to workstations such that the sum of the task times assigned to each workstation is as close to the takt time as possible without exceeding it.

For the first workstation, we can assign task A (45 seconds). For the second workstation, we can assign tasks B and D (50+55=105 seconds).

This leaves us with 7.5*60-45-105=270 seconds for the third workstation. The longest task available is F (65 seconds), so we can assign task F to the third workstation.

If we were to assign tasks C, E, and G to the third workstation (20+15+25=60 seconds), the total task time for that workstation would only be 60+35=95 seconds, which is much less than the available time. This would create a bottleneck and result in underutilization of the workstations before it. So, C, E, and G should not be assigned to the third workstation.

Therefore, the best choice is D, with a task time of 55 seconds.

Question 13

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. What is the theoretical minimum number of stations that will be used if the line is balanced using the appropriate takt time?

Accepted Answer

To determine the minimum number of stations required, we need to calculate the theoretical minimum number of stations (balance delay). The takt time is the total available time divided by the required output rate. The required output rate is 400 units divided by the available time of 7.5 hours or 27 seconds per unit.

We then calculate the minimum cycle time by adding up the longest task time for each step. Starting with Task A, the longest task time is 45 seconds. For Task B and Task C, we choose Task B as it has a longer duration of 50 seconds. For Task D, the longest task time is 55 seconds. For Task E and Task F, we choose Task F as it has a longer duration of 65 seconds. For Task G, the task time is 25 seconds. Finally, for Task H, the task time is 35 seconds.

The minimum cycle time is therefore 45 + 50 + 55 + 65 + 35 = 250 seconds.

To determine the minimum number of stations required, we divide the sum of the task times by the cycle time and round up to the nearest integer.

Sum of task times = 45 + 50 + 20 + 55 + 15 + 65 + 25 + 35 = 310 seconds.

Minimum number of stations required = ceil (310/250) = 2.

Therefore, the theoretical minimum number of stations required is 2. However, we need to round up to the next odd number to avoid creating unbalanced stations. Therefore, the minimum number of stations required is 3. We can assign tasks to workstations to fill up as much takt time as possible, starting with the longest task time and breaking ties by assigning the longest task first.

Station 1: Tasks F (65 sec) + B (50 sec) + A (45 sec) = 160 seconds 
Station 2: Tasks D (55 sec) + C (20 sec) + E (15 sec) = 90 seconds 
Station 3: Task H (35 sec) + G (25 sec) + A (45 sec) = 105 seconds

Each station has a total duration less than or equal to the cycle time of 250 seconds, and the line is balanced. Therefore, the best choice is C, 5 stations.

Question 14

Where should a business consultant position herself on the three axes of contact, customization, and cost.

Accepted Answer

The answer of Where should a business consultant position herself...

Question 15

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. How many workstations must be added to increase the output rate to one unit per minute?

Accepted Answer

To calculate the output rate, we need to first calculate the cycle time or takt time:

$$ 	ext{Cycle time} = \frac{	ext{Available production time}}{	ext{Required daily units}} = \frac{7.5 	ext{ hours} 	imes 3600 	ext{ sec/hour}}{400 	ext{ units}} = 67.5 	ext{ sec/unit}$$

From the table, we can assign tasks to different workstations to create a balanced line with the longest task assigned first in case of a tie:

| Workstation 1 | Workstation 2 | Workstation 3 | Workstation 4 |
|---------------|---------------|---------------|---------------|
| D             | F             | A             | B             |
| E             | H             | C             |               |
| G             |               |               |               |

We can see that there are four workstations required to produce one unit per minute, so the answer is (C) 3.

Question 16

Champion Cooling has just signed a contract to assemble window air conditioners for another company. The list of tasks, including time requirements and immediate predecessors, follows. Each task may not be shortened. Initially, the plan was to make 300 units in an eight hour day but as the summer months approach, Champion Cooling finds themselves far behind in total production. They wish to reconfigure their production line in order to produce maximum output. What should their takt time be? $$\begin{array} { | l | c | c | } 
\hline \text { Task } & \text { Time (min) } & \text { Predecessor } \
\hline \text { Bolt compressor to base } & 5 & \text { None } \
\hline \text { Install coils and lines } & 6 & \text { Bolt compressor to base } \
\hline \text { Install fan motor } & 7 & \text { Install coils and lines } \
\hline \text { Install switch and thermostat } & 5 & \text { Install fan motor } \
\hline \text { Charge system and test } & 10 & \text { Install switch and thermostat } \
\hline \text { Cosmetic detailing } & 7 & \text { Charge system and test } \
\hline
\end{array}$$

Accepted Answer

The total time required to produce one unit is the sum of all task times, which is 5 + 6 + 7 + 5 + 10 + 7 = 40 minutes. To find the takt time, which is the maximum amount of time each step should take to meet demand, divide the total available work time in minutes by the desired output. For an 8-hour day (480 minutes) aiming to produce 300 units, the takt time is 480 minutes / 300 units = 1.6 minutes. However, since the question asks for the takt time to produce maximum output, the limiting factor is the longest task, which is "Charge system and test" at 10 minutes. This means the production line can only complete a unit every 10 minutes at best, setting the takt time to 10 minutes to achieve maximum output given the constraints.

Question 17

Which poses the greatest underlying managerial challenges - a service that is extremely high on customization, contact, and tangibility or perchance a service that is extremely low on contact, customization and tangibility? Provide an example of a service that fits each space and defend your answer.

Accepted Answer

The answer of Which poses the greatest underlying managerial challenges...

Question 18

Define the terms front room and back room and describe the roles these processes play in service operations. What must operations managers take into consideration when setting up these two processes?

Accepted Answer

The answer of Define the terms front room and back...

Question 19

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 7.5 productive hours available in a day and the manufacturer wishes to produce 400 units. Balance the line by assigning tasks to workstations to fill up as much takt time as possible. Break ties by assigning the longest task first.
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \text { A } & 45 & \cdots \
\hline \text { B } & 50 & \text { A } \
\hline \text { C } & 20 & \text { A } \
\hline \text { D } & 55 & \text { A } \
\hline \text { E } & 15 & \text { D } \
\hline \text { F } & 65 & \text { D } \
\hline \text { G } & 25 & \text { E } \
\hline \text { H } & 35 & \text { B, C, F, G } \
\hline
\end{array}$$
-Refer to the scenario above. The process engineer calculates the takt time and examines the task times indicated in the table. He decides to use the minimum cycle time instead and have the workers leave early each day once they have built 400 units. How much earlier would the workers leave?

Accepted Answer

First, calculate the takt time: $ \text{Takt time} = \frac{\text{Available time per day}}{\text{Demand per day}} $. With 7.5 hours available (450 minutes or 27,000 seconds) and a demand of 400 units, the takt time is $ \frac{27000}{400} = 67.5 $ seconds per unit. The minimum cycle time is determined by the longest task, which is task F at 65 seconds. Since the takt time is 67.5 seconds and the longest task dictates a cycle time of 65 seconds, the line operates at the cycle time of 65 seconds, not the takt time. The difference in time saved per unit is $ 67.5 - 65 = 2.5 $ seconds. Over 400 units, this amounts to $ 400 \times 2.5 = 1000 $ seconds saved, or $ 16 $ minutes and $ 40 $ seconds.

Question 20

Use this scenario for the following question(s).
The process design team at a manufacturer has broken an assembly process into eight basic steps, each with a required time, and predecessor as shown in the table. There are 8 productive hours available in a day and the manufacturer wishes to produce 400 units. Use this information to answer the following question(s).
 $$\begin{array} { | c | c | c | } 
\hline \text { Task } & \text { Time } ( \mathrm { sec } ) & \text { Predecessor } \
\hline \mathrm { J } & 45 & \cdots \
\hline \text { K } & 50 & \mathrm {~J} \
\hline \mathrm { L } & 40 & \mathrm {~J} \
\hline \mathrm { M } & 55 & \mathrm {~K} , \mathrm {~L} \
\hline \mathrm { N } & 40 & \mathrm { M } \
\hline \mathrm { O } & 65 & \mathrm { M } \
\hline \text { P } & 25 & \mathrm {~N} \
\hline \text { R } & 35 & \mathrm { O } , \mathrm { P } \
\hline
\end{array}$$
-Refer to the scenario above. Operations managers and process engineers design a line that contains seven stations. What is the percentage of idle time?

Accepted Answer

The correct answer is A because the total time required to produce one unit is 355 seconds, and the available productive time is 28,800 seconds (8 hours * 60 minutes * 60 seconds). Therefore, the idle time is 28,800 - 400 * 355 = 6,280 seconds, and the percentage of idle time is 6,280 / 28,800 * 100% = 21.9%.

Quiz 3: Process Choice and Layout Decisions in Manufacturing and Services

Name a service business that relies heavily on intangible activities. How does the level of intangibility fit with the degrees of contact and customization?

Name two restaurants that score differently on at least two scales in the service positioning space and provide examples of how they differ.

Where should a business consultant position herself on the three axes of contact, customization, and cost.

Define the terms front room and back room and describe the roles these processes play in service operations. What must operations managers take into consideration when setting up these two processes?