Operations Management Chapter 8
Total idle time is calculated using the equation:
(N)(CT)-∑t
Marketing Products Inc. uses an assembly line consisting of three workstations. Management is considering demand forecasts/output rate of 300, 400, 500, and 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet: Task 1 = 0.5 min, Task 2 = 0.75 min, Task 3 = 1.0 min, and Task 4 = 0.75 min. Using the formula CT = Available Time (A)/ Demand Forecast (R), to compute the cycle time, identify the demand forecast (R) that will not require redefining task work content.
300 units
TopToes Inc., a shoe company, assembles gym shoes in an assembly line using 10 workstations. The target output for an 8 hour workday is 240 shoes. The sum of the task times is 18 minutes/shoe. The cycle time is 2 minutes/shoe. The assembly-line efficiency of TopToes Inc. is _____.
90%
Megan plans the facility layout of her new shop that would sell a variety of healthcare industry machines. She arranges the machines in a way that the machines are grouped according to their functions. Which of the following types of facility layouts has Megan used in her shop?
A process layout
_____ is the interval between successive outputs coming off the assembly line.
Cycle time
_____ layouts usually require a high level of planning and control compared with other types of facility layouts.
Fixed-position
Which of the following is a limitation of a process layout?
It has higher worker skill requirements.
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the information tables, determine which tasks may be assigned to which workstation without violating precedence and without exceeding the cycle time. Which task(s) can be assigned to Workstation B and what is the Total Task Time for Workstation B? Assumptions are: no restrictions for combination of tasks other than logical precedence restrictions: example, pages may not be attached to cover prior to having been selected; no restrictions for transfer of work components in task; and, each workstation currently completes all six tasks.
Tasks 2, 3, and 4; 1.25 min
In the context of facility layouts, which of the following is true of process layouts?
They require more complicated planning and control systems.
_____ is a systematic procedure for the analysis of work, and determination of standard times required to perform key tasks in a process.
Work measurement
Compared to other type of layouts, fixed-position layouts require
a high level of planning and control
Minimizing imbalance among workstations while trying to achieve a desired output rate is known as _____.
assembly-line balancing
Job _____ involves determining the specific job tasks and responsibilities, the work environment, and the methods by which the tasks will be carried out to meet the goals of operations.
design
The objective of assembly-line balancing is to:
minimize the imbalance among workstations while trying to achieve a desired output rate.
One of the differences between product layouts and process layouts is that unlike product layouts, process layouts:
provide more flexibility.
According to a study conducted by Software Advice, a consumer is more likely to buy a product that has:
reduced environmental impact.
Compared to product layouts, process layouts:
require a lower investment in equipment.
In a _____ team, members communicate by computer, take turns as leaders, and join and leave the team as necessary.
virtual
Marketing Products Inc. uses an assembly line consisting of three workstations. Management expects an output rate of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the formula Total Idle Time = [Number of Workstations (N) × Cycle Time (CT)] - Sum of Task Times (∑t), compute the total idle time.
0.9 min per pamphlet
An assembly line with 24 activities is to be balanced. The total amount of time required for all 24 activities is 36 minutes. The line will operate for 400 minutes per day. The cycle time (CT) must be _____ minute(s) to achieve an output rate of 200 units/day.
2.0
Identify the most suitable layout for a facility that handles a wide variety of customized orders
A process layout
Which of following facilities is most likely to have a fixed-position layout?
An airplane factory
Marketing Products Inc. uses an assembly line consisting of five workstations and a Demand Forecast of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. Management is considering line balancing approaches to achieve a demand forecast/output rate of 700. The sum of the task times is three minutes per pamphlet. Using the formula Theoretical Minimum Number of Workstations Required: = Sum of Task Times/Cycle Time = Σt /CT, calculate the minimum number of workstations required to support the new demand forecast, calculate the associated Assembly-Line Efficiency Rate, Σt/(N * CT) for the three workstations and then for the calculated minimum number of workstations and interpret results in terms of assembly-line efficiency and balance-delay.
Decrease in assembly-line efficiency rate: -2.57%; Increase in balance-delay: 2.57%
______ is NOT an objective of ergonomics.
Increase the cost of training
Which of the following is an objective of ergonomics?
To reduce energy requirements while increasing accuracy
A U-shaped arrangement of machines that permits materials to move clockwise or counterclockwise from one operation to the next is characteristic of a _____ layout.
cellular
_______ layouts facilitate the processing of families of parts with similar processing requirements. The procedure of classifying parts into such families is called _______
cellular; group technology
In designing process layouts, the _____ of each department is used to compute distances and materials-handling costs for a particular layout.
centroid
In general, work centers with a large number of moves between them should be located
close to one another.
One of the objectives of facility layout and work design in a goods producing organization is to
enhance sustainability
Job ______ is the horizontal expansion of the job to give the worker more variety, while job _____ is the vertical expansion of job duties to give the worker more responsibility.
enlargement; enrichment
Bottlenecks are the result of _____.
lack-of-work delay
A _____ layout is an arrangement of physical facilities based on the sequence of operations that is performed during the manufacturing of a good or delivery of a service.
product
A key difference between a process layout and a product layout is that process layouts
provide more flexibility
A(n) _____ is the development of a standard time by observing a task with the use of a stopwatch and analyzing the data.
time study
Marketing Products Inc. uses an assembly line consisting of five workstations and a Demand Forecast of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet: Task 1 = 1.0; Task 2 =0.5; Task 3 =0 .25; Task 4 =0.5; Task 5 = 0.5; Task 6 = 0.25. Using the following table determine which tasks might most efficiently be restructured to accommodate the computed cycle time. Assumptions are: 1) restrictions for combination of tasks are that Task 1 can be broken down into four work components of 0.40, 0.30, 0.15, and 0.15; Tasks 4 and 6 may not be combined or altered; 2) no restrictions for transfer of work components in tasks; and, 3) each workstation completes all six tasks. Using the following table, if necessary, restructure the components of Task 1 and redistribute overage components to Tasks 2, 3, or 5. What summary time value will be assigned to Task 3 after restructuring? If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements
0.55
Marketing Products Inc. uses an assembly line consisting of five workstations and a Demand Forecast of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet: Task 1 = 1.0; Task 2 =0.5; Task 3 =0 .25; Task 4 =0.5; Task 5 = 0.5; Task 6 = 0.25. Using the following table determine which tasks might most efficiently be restructured to accommodate the computed cycle time. Assumptions are: 1) restrictions for combination of tasks are that Task 1 can be broken down into five equal components and Task 6 may not be combined or altered; 2) no restrictions for transfer of work components in tasks; and, 3) each workstation completes all six tasks. Using the following table, if necessary, restructure the components of Task 1 and redistribute overage components to Tasks 2-6. What is the maximum summary time value of the of Task 1? If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements.
0.60
Marketing Products Inc. uses an assembly line consisting of five workstations and a Demand Forecast of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet: Task 1 = 1.0; Task 2 =0.5; Task 3 =0 .25; Task 4 =0.5; Task 5 = 0.5; Task 6 = 0.25. Using the following table determine which tasks might most efficiently be restructured to accommodate the computed cycle time. Assumptions are: 1) restrictions for combination of tasks are that Task 1 can be broken down into five equal components and Task 6 may not be combined or altered; 2) no restrictions for transfer of work components in tasks; and, 3) each workstation completes all six tasks. Using the following table, if necessary, restructure the components of Task 1 and redistribute overage components to Tasks 2-6. What is the resulting summary time value of the of Task 3? If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements.
0.65
Marketing Products Inc. uses an assembly line consisting of five workstations and a Demand Forecast of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet: Task 1 = 1.0; Task 2 =0.5; Task 3 =0 .25; Task 4 =0.5; Task 5 = 0.5; Task 6 = 0.25. Using the following table determine which tasks might most efficiently be restructured to accommodate the computed cycle time. Assumptions are: 1) restrictions for combination of tasks are that Task 1 can be broken down into five work components of 0.25, 0.25, 0.20, 0.15, 0.15; Task 6 may not be combined or altered; 2) no restrictions for transfer of work components in tasks; and, 3) each workstation completes all six tasks. Using the following table, if necessary, restructure the components of Task 1 and redistribute overage components to Tasks 2-5. What is the resulting summary time value of Tasks 1, 2, and 3? If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements.
0.65, 0.65, and 0.45
An assembly line with 28 activities is to be balanced. The total amount of time required for all 28 activities is 39 minutes. The line will operate for 300 minutes per day. Which of the following must be the cycle time (CT) to achieve an output rate of 250 units/day?
1.2 minutes
Marketing Products Inc. uses an assembly line consisting of three workstations. Management expects an output rate of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the formula Cycle Time (CT) = Available Time (A)/ Demand Forecast (R), compute the cycle time.
1.3 min per unit
An assembly line with 30 activities is to be balanced. The total amount of time required for all 30 activities is 45 minutes. The line will operate for 420 minutes per day. Which of the following must be the cycle time to achieve an output rate of 300 units/day?
1.4 minutes
Marketing Products Inc. uses an assembly line consisting of three workstations. Management expects an output rate of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the formula Balance Delay = 1 - Assembly-Line Efficiency, compute the balance delay rate, the amount of idle time resulting from imbalance among workstations.
23.08%
Three work study analysts are rating an employee. Work study analyst 1 rates the employee at PRF = 1.0 and an observed time of 3.0 minutes per unit. Work study analyst 2 rates the employee at PRF = 0.8 and an observed time of 2.9 minutes per unit. Work study analyst 3 rates the employee at PRF = 1.1 and an observed time of 3.1 minutes per unit. What should the standard time be, assuming an allowance factor of 15%?
3.3465 minutes per unit.
Three work study analysts are rating an employee. Work study analyst 1 rates the employee at PRF = 1.0 and an observed time of 3.0 minutes per unit. Work study analyst 2 rates the employee at PRF = 0.8 and an observed time of 2.9 minutes per unit. Work study analyst 3 rates the employee at PRF = 1.1 and an observed time of 3.1 minutes per unit. What should the standard time be, assuming an allowance factor of 20%?
3.3492 minutes per unit
Marketing Products Inc. uses an assembly line consisting of three workstations. Management is considering line balancing approaches to achieve a demand forecast/output rate of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the formula Theoretical Minimum Number of Workstations Required: = Sum of Task Times/Cycle Time = ∑t /CT, calculate the minimum number of workstations required to support the demand forecast.
5.00
FancyTrends Inc., a handbag manufacturing company, assembles handbags in an assembly line using 10 workstations. The target output for an 8 hour workday is 120 bags. The sum of the task times is 30 minutes/bag. The cycle time is 4 minutes/bag. The assembly-line efficiency is _____.
75%
Marketing Products Inc. uses an assembly line consisting of three workstations. Management expects an output rate of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the formula Efficiency = Sum of Task Times (∑t) / [Number of Workstations (N) x Cycle Time (CT)], compute the assembly-line efficiency rate.
76.92%
Marketing Products Inc. uses an assembly line consisting of three workstations. Management is considering line balancing approaches to achieve a demand forecast/output rate of 600 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the formula Theoretical Minimum Number of Workstations Required: = Sum of Task Times/Cycle Time = ∑t /CT, calculate the minimum number of workstations required to support the demand forecast and then calculate the associated Assembly-Line Efficiency Rate, ∑t/(N * CT).
92.31%
Which of the following types of facility layouts is best suited for a heavy machine tools factory?
A fixed-position layout
Which of the following facility layouts is used by service organizations that provide highly standardized services?
A product layout
_____ is a technique to group tasks among workstations so that each workstation has—in the ideal case—the same amount of work.
Assembly-line balancing
_____ is concerned with improving productivity and safety by designing workplaces, equipment, instruments, computers, workstations, and so on that take into account the physical capabilities of people.
Ergonomics
Which is the basic trade-off in selecting among layout types?
Flexibility versus productivity
_____ occurs when a work center completes a unit but cannot release it because the in-process storage at the next stage is full.
Flow-blocking delay
In the context of assembly-line balancing, _____ is the difference between total time available and the sum of the actual times for productive tasks.
Idle time
________ is NOT an example of a use of work measurement.
Implementing new work procedures, regardless of cost
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. Management is considering line balancing approaches to achieve a demand forecast/output rate of 600. The sum of the task times is three minutes per pamphlet. Using the formula Theoretical Minimum Number of Workstations Required: = Sum of Task Times/Cycle Time = Σt /CT, calculate the minimum number of workstations required to support the new demand forecast, calculate the associated Assembly-Line Efficiency Rate, Σt/(N * CT) for the three workstations and then for the calculated minimum number of workstations and interpret results in terms of assembly-line efficiency and balance-delay.
Increase in assembly-line efficiency rate: 15.39%; Decrease in balance-delay: -15.39%
In the context of facility layout, which of the following is true of a fixed-position layout?
It has moderate flexibility.
Which of the following is true of ergonomics?
It helps reduce fatigue.
Which of the following is true of a cellular layout?
It is not designed according to the functional characteristics of equipment.
Which of the following is true of a cellular layout?
It reduces materials-handling requirements.
In the context of facility layouts, which of the following is true of a product layout?
It supports a smooth and logical flow where all goods or services move in a continuous path from one process stage to the next.
_____ is vertical expansion of job duties to give the worker more responsibility.
Job enrichment
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the information tables, determine which tasks may be assigned to which workstation without violating precedence and without exceeding the cycle time. If Tasks 1 and 6 were assigned to Workstation A, what would be the result of this assignment? Assumptions are: no restrictions for combination of tasks other than logical precedence restrictions: example, pages may not be attached to cover prior to having been selected; no restrictions for transfer of work components in task; and, each workstation currently completes all six tasks.
Precedence is not appropriate/logical; cycle time is not exceeded
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the information tables, determine which tasks may be assigned to which workstation without violating precedence and without exceeding the cycle time. Which task(s) can be assigned to Workstation A and what is the Total Task Time for Workstation A? Assumptions are: no restrictions for combination of tasks other than logical precedence restrictions: example, pages may not be attached to cover prior to having been selected; no restrictions for transfer of work components in task; and, each workstation currently completes all six tasks.
Task 1; 1.0 min
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. Management is considering line balancing approaches to achieve a demand forecast/output rate of 600. The sum of the task times is three minutes per pamphlet: Task 1 = 1.0; Task 2 =0.5; Task 3 =0 .25; Task 4 =0.5; Task 5 = 0.5; Task 6 = 0.25. Using the following table determine which tasks might most efficiently be restructured to accommodate the computed cycle time. Assumptions are: 1) no restrictions for combination of tasks; 2) no restrictions for transfer of work components in task; and, 3) each workstation completes all six tasks. If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements.
Tasks 1 and 3
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. Management is considering line balancing approaches to achieve a demand forecast/output rate of 600. The sum of the task times is three minutes per pamphlet: Task 1 = 1.0; Task 2 =0.5; Task 3 =0 .25; Task 4 =0.5; Task 5 = 0.5; Task 6 = 0.25. Using the following table determine which tasks might most efficiently be restructured to accommodate the computed cycle time. Assumptions are: 1) restrictions for combination of Tasks 3 and 6: no changes in sequence and no changes in time to perform; 2) no restrictions for transfer of work components in task; and, 3) each workstation completes all six tasks. If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements.
Tasks 1, 2, 4, and 5
Marketing Products Inc. uses an assembly line consisting of three workstations and a Demand Forecast of 300 pamphlets per eight-hour day less one hour for lunch and two 15-minute breaks. The sum of the task times is three minutes per pamphlet. Using the information tables, determine which tasks may be assigned to which workstation without violating precedence and without exceeding the cycle time. Which task(s) can be assigned to Workstation C and what is the Total Task Time for Workstation C? Assumptions are: no restrictions for combination of tasks other than logical precedence restrictions: example, pages may not be attached to cover prior to having been selected; no restrictions for transfer of work components in task; and, each workstation currently completes all six tasks If required cycle time (CT) < largest task time, work content must be redefined by splitting some tasks into smaller elements.
Tasks 5 and 6; 0.75 min
Which of the following is true of fixed-position layouts?
The automation potential is moderate.
The first approach to designing process layouts is used when it is difficult to obtain data on costs or volumes moved between departments. The second approach focuses on the costs associated with moving materials. Identify a major difference between these two approaches.
The first approach relies on a preference table that specifies the importance of two departments being close to one another while the second approach relies on materials-handling costs as the primary criterion.
A(n) _____ is a product layout dedicated to combining the components of a good or service that has been created previously.
assembly line
A facility arrangement that is made up of self-contained groups of equipment needed for producing a particular set of goods or services is a _____ layout.
cellular
A _____ layout consolidates the resources necessary to deliver a good or service in one physical location.
fixed-position
The production of large goods such as ships is best accomplished using a _____ layout.
fixed-position
In a cellular layout, the procedure of classifying parts with similar processing requirements into families is called _____.
group technology
One of the advantages of a product layout is that it:
has low work-in-process inventories.
A(n) ______ causes bottlenecks, which limits the throughput of the entire process.
lack-of-work delay
Cycle time cannot be smaller than the ______ , nor can it be larger than the _______
largest operation time; sum of all operation times
Work centers with a large number of moves between them should be
located close to one another
One of the disadvantages of a product layout is that it has:
low flexibility.
_______ is the expected time required to perform some work activity at a normal pace, under normal operating conditions, and using a prescribed method. This can be found using the equation _______.
normal time; OT x PRF
In both good-producing and service-providing organizations, _____ is the key to providing value and ensuring customer satisfaction.
optimizing integration of facility layout and work design
A facility arrangement that consists of a functional grouping of equipment or activities that do similar work is a _____ layout.
process
In designing _____ layouts, one is concerned with the arrangement of departments or work centers relative to each other.
process
Organizations that need the ability to provide a wide variety of services to customers with differing requirements usually use a _____ layout.
process
Service organizations who need the ability to provide a wide variety of services to customers with differing requirements usually use a _____ layout.
process
Service organizations that provide highly standardized services, such as a pizza kitchen or a Chipotle restaurant, tend to use a ______ type of facility layout.
product
