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Operations Management: Processes and Supply Chains, 10e (Krajewski et al.)Chapter 7 Constraint Management

1) A bottleneck is an operation that has the lowest effective capacity of any operation in the process.Answer: TRUEReference: IntroductionDifficulty: ModerateKeywords: bottleneck, effective capacity

2) The process with the least capacity is called a bottleneck if its output is less than market demand.Answer: TRUEReference: IntroductionDifficulty: ModerateKeywords: bottleneck, capacity

3) The process with the least capacity is called a bottleneck if its output is still greater than the market demand.Answer: FALSEReference: IntroductionDifficulty: ModerateKeywords: bottleneck, capacity

4) Operating processes close to their capacity can result in low customer satisfaction and even losing money despite high sales levels.Answer: TRUEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: capacity, customer satisfactionLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

5) The Theory of Constraints method is also referred to as the drum-buffer-rope method.Answer: TRUEReference: The Theory of ConstraintsDifficulty: EasyKeywords: TOC, theory of constraints, drum-buffer-rope

6) According to the Theory of Constraints, the four operational measures include inventory, throughput, delivery lead times and utilization.Answer: FALSEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, capacity measures, inventory, throughput, operating expense, utilization

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7) A business school with plenty of classroom space that hires adjunct faculty for a semester to meet unusually high student demand for courses is an example of elevating a bottleneck.Answer: TRUEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: elevate bottleneck, TOC

8) Any system composed of resources that are operating at maximum output will, by definition, have maximum output for the entire system.Answer: FALSEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: constraint, bottleneck, TOC

9) In a shop managed according to TOC principles, inventory is needed only in front of bottlenecks in order to prevent them from sitting idle.Answer: FALSEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, buffer

10) The first step in applying the Theory of Constraints is to identify the constraint.Answer: TRUEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: constraint, bottleneck, TOC

11) The final step in applying the Theory of Constraints is to repeat the first four steps.Answer: TRUEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: inertia, TOC

12) Lanny discovers that the bottleneck is the riveting machine so he schedules all production around when that machine is available. This is an example of elevating the constraint in the five-step constraint management process.Answer: FALSEReference: The Theory of ConstraintsDifficulty: ModerateKeywords: exploit constraint, TOC

13) A bottleneck process has the lowest capacity and the longest total time from the start to the finish.Answer: TRUEReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck process, lowest capacity, longest total timeLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

14) A competent operations manager should first eliminate all of the bottlenecks from the process.Answer: FALSEReference: Identification and Management of BottlenecksDifficulty: Moderate


Keywords: bottleneck processLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

15) Short term capacity planning should be driven by identification and management of bottlenecks.Answer: TRUEReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: capacity planning, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

16) Line balancing is the assignment of work to stations in a line to achieve the desired output rate with the smallest number of workstations.Answer: TRUEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balance, workstations, lineLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

17) Line balancing strives to create workstations so that the capacity utilization for the bottleneck is much higher than for the other workstations in the line.Answer: FALSEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balance, workstations, line, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

18) Line balancing applies only to line processes that do assembly work, or to work that can be bundled in many ways to create the jobs for each workstation in the line.Answer: TRUEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balance, workstations, lineLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

19) Immediate predecessors are the smallest units of work that can be performed independently.Answer: FALSEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: predecessor, work, task

20) The balance delay is the amount by which efficiency falls short of 100 percent.Answer: TRUEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: balance delay, efficiency

21) To generate the maximum output, the cycle time should be set as the longest elemental task time.Answer: TRUE


Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: cycle time, output, taskLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

22) Paced lines require that inventory storage areas be placed between stations.Answer: FALSEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: paced line, inventory

23) A mixed-model line produces several items belonging to the same family.Answer: TRUEReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: mixed model line, family

24) The focus for a process improvement exercise should be on balancing:A) flow.B) capacity.C) workload.D) time.Answer: AReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, theory of constraints, flowLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

25) According to the Theory of Constraints, the four operational measures of capacity include all of the following EXCEPT:A) inventory.B) throughput.C) utilization.D) delivery lead times.Answer: DReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, capacity measures, inventory, throughput, operating expense, utilization

26) Practical application of the Theory of Constraints involves the implementation of all of the following steps EXCEPT:A) Identify the system bottleneck(s).B) Exploit the bottleneck(s).C) Reduce the capacity at the bottleneck(s).D) Elevate the bottleneck(s).Answer: CReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, capacity measures, inventory, throughput, operating expense, utilization

27) Consider consecutive processes A-B-C, where process A has a capacity of 20 units per hour, process B has a capacity of 25 units per hour, and process C has a capacity of 30 units per hour. Where would an operations manager want any inventory?A) in front of process A


B) in front of process BC) in front of process CD) Inventory should not exist anywhere.Answer: AReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, theory of constraints, inventoryLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

28) Use the process flow diagram to determine which of these events has the greatest net benefit.

A) reducing the flow time at Station A from 8 to 7 minutesB) increasing the capacity at Station B to 8 units per hourC) increasing the capacity at Station C to 7 units per hourD) reducing the flow time at Station D from 9 to 8 minutesAnswer: CReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, theory of constraints, bottleneckAACSB: Analytic skills



A) reducing the flow time at Station A from 10 to 8 minutesB) increasing the capacity at Station B to 12 units per hourC) increasing the capacity at Station C to 10 units per hourD) reducing the flow time at Station D from 12 to 10 minutesAnswer: DReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, theory of constraints, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.AACSB: Analytic skills


A) reducing the flow time at Station A from 8 to 7 minutesB) increasing the capacity at Station B to 12 units per hourC) increasing the capacity at Station C to 9 units per hourD) reducing the flow time at Station D from 6 to 5 minutesAnswer: AReference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, theory of constraints, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.AACSB: Analytic skills

31) Work should be released into the system when:A) a customer order is received.B) the first step in the process is idle.C) a customer order is completed.D) the bottlenecks need work.Answer: DReference: The Theory of ConstraintsDifficulty: EasyKeywords: TOC, theory of constraints, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

32) The second step in Theory of Constraints application, "exploit the bottleneck(s)," means that the analyst should:A) create a schedule that maximizes the throughput of the bottlenecks.B) repeat the analysis process to look for other bottlenecks.


C) consider increasing capacity of the bottleneck.D) schedule non-bottleneck resources to support the bottleneck.Answer: AReference: The Theory of ConstraintsDifficulty: ModerateKeywords: bottleneck, TOC, theory of constraintsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

33) The third step in Theory of Constraints application, "subordinate all other decisions to Step 2," means that the analyst should:A) wait for authorization before proceeding with any system-wide changes.B) schedule non-bottleneck processes to support the bottleneck schedule.C) seek to increase capacity of only the bottleneck resources.D) should seek to increase capacity of both the bottleneck and non-bottleneck resources.Answer: BReference: The Theory of ConstraintsDifficulty: ModerateKeywords: bottleneck, TOC, theory of constraintsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

34) The fourth step in Theory of Constraints application, "elevate the bottleneck(s)," means that the analyst should:A) create a schedule that maximizes the throughput of the bottlenecks.B) repeat the analysis process to look for other bottlenecks.C) consider increasing capacity of the bottleneck.D) schedule non-bottleneck resources to support the bottleneck.Answer: CReference: The Theory of ConstraintsDifficulty: ModerateKeywords: bottleneck, TOC, theory of constraintsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.


35) The fifth step in Theory of Constraints application, "do not let inertia set in," means that the analyst should:A) create a schedule that maximizes the throughput of the bottlenecks.B) repeat the analysis to identify and manage new set of constraints.C) consider increasing capacity of the bottleneck.D) schedule non-bottleneck resources to support the bottleneck.Answer: BReference: The Theory of ConstraintsDifficulty: ModerateKeywords: bottleneck, TOC, theory of constraintsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

36) Which of the following statements regarding setups is TRUE?A) Unusually high setup times result in higher utilization.B) Processes are generating output throughout the entire setup process.C) A machine used in a line process would probably have fewer setups than a batch process.D) A TOC analyst would not be concerned with setup times on non-bottleneck machines.Answer: DReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: setup, TOC, bottleneck

37) There are three consecutive steps in a customer service process. The first two steps are each capable of serving 25 customers per hour while the third step can process only 20 customers per hour. Which of the following statements regarding this system is true?A) The entire system is capable of processing 25 customers per hour.B) There are floating bottlenecks in the system.C) If the first two steps are run at full capacity, then the third step has a waiting line.D) The first and second steps are bottlenecks for the system.Answer: CReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: capacity, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.


Table 7.1

The figure above shows the call routing process for a customer service call center. Incoming calls are routed, depending on the complexity of the caller's request. Simple request are routed to work center B, while the more complex calls are routed to work center C (which also takes simple calls when not busy). The numbers in parentheses are the time in minutes for each step of the process.

38) Use the information in Table 7.1. What is the throughput time for the process, assuming that the Call Center is always busy and has customers waiting to be processed?A) 24 minutesB) 18 minutesC) 20 minutesD) 22 minutesAnswer: BReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills

39) Use the information in Table 7.1. What is the process bottleneck?A) AB) B and C togetherC) DD) EAnswer: CReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: process bottleneckAACSB: Analytic skills

40) Use the information in Table 7.1. What is the 8-hour capacity for the process?A) 24 callsB) 17.1 callsC) 40 callsD) 48 callsAnswer: DReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, capacityAACSB: Analytic skills


41) Use the information in Table 7.1. Where would you expect customer wait times to occur?A) D onlyB) C and DC) A onlyD) E onlyAnswer: BReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, capacity, customer wait times

Table 7.2

The figure above shows the process for paying tuition at a major university. Students are provided their bill for the next term for review, then routed to different tables for questions to be answered before finally paying their tuition at E. The numbers in parentheses are the time in minutes for each step of the process.

42) Use the information in Table 7.2. What is the throughput time for the A-B-C-E process route?A) 17 minutesB) 27 minutesC) 21 minutesD) 19 minutesAnswer: AReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills

43) Use the information in Table 7.2. What is the throughput time for the A-B-D-E process route?A) 17 minutesB) 27 minutesC) 21 minutesD) 19 minutesAnswer: CReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills


44) Use the information in Table 7.2. What is the capacity for the A-B-C-E process route?A) 10 students per hourB) 6 student per hourC) 3.5 students per hourD) 2.9 students per hourAnswer: AReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, throughput timeAACSB: Analytic skills

45) Use the information in Table 7.2. What is the capacity for the A-B-D-E process route?A) 10 students per hourB) 6 student per hourC) 3.5 students per hourD) 2.9 students per hourAnswer: BReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, throughput timeAACSB: Analytic skills

46) Use the information in Table 7.2. If 60% of the students are routed to C and 40% are routed to D, what is the average capacity per hour for the process?A) 10 students per hourB) 6.5 student per hourC) 8 students per hourD) 8.4 students per hourAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: bottleneck, capacityAACSB: Analytic skills

47) Use the information in Table 7.2. Where would you expect student wait times to occur?A) D onlyB) B, C and DC) A onlyD) E onlyAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: bottleneck, capacity, customer wait timesAACSB: Analytic skills


Table 7.3

The figure above shows the process for customers arriving at Pierre's Spa and Salon. After signing in, customers are routed to different locations in the Spa for the two different services provided. The numbers in parentheses are the time in minutes for each step of the process.

48) Use the information in Table 7.3. What is the throughput time for the A-B-C-D -H routing?A) 48 minutesB) 30 minutesC) 53 minutesD) 23 minutesAnswer: CReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills

49) Use the information in Table 7.3. What is the throughput time for the A-B-E-F-G-H routing?A) 48 minutesB) 30 minutesC) 53 minutesD) 23 minutesAnswer: AReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills

50) Use the information in Table 7.3. What is the process bottleneck?A) HB) BC) CD) DAnswer: DReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, throughput time


Table 7.4

The figure above shows the process for customers arriving at Hobbies Unlimited for several advertised crafts demonstrations. After signing in, customers are routed to different locations in the store for the two different programs provided. The numbers in parentheses are the time in minutes for each step of the process.

51) Use the information in Table 7.4. What is the throughput time for the A-B-C-D-G routing?A) 25 minutesB) 70 minutesC) 105 minutesD) 60 minutesAnswer: DReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills

52) Use the information in Table 7.4. What is the throughput time for the A-B-E-F-G routing?A) 25 minutesB) 70 minutesC) 105 minutesD) 60 minutesAnswer: BReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: bottleneck, throughput timeAACSB: Analytic skills

53) Use the information in Table 7.4. How many customers can be processed through the A-B-C-D-G routing during a 4-hour evening session?A) 48B) 24C) 32D) 12Answer: DReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, throughput timeAACSB: Analytic skills


54) Use the information in Table 7.4. How many customers can be processed through the A-B-E-F-G routing during a 4-hour evening session?A) 8B) 24C) 12D) 32Answer: AReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneck, throughput timeAACSB: Analytic skills

Table 7.5A company makes four products that have the following characteristics: Product A sells for $50 but needs $10 of materials and $15 of labor to produce; Product B sells for $75 but needs $30 of materials and $15 of labor to produce; Product C sells for $100 but needs $50 of materials and $30 of labor to produce; Product D sells for $150 but needs $75 of materials and $40 of labor to produce. The processing requirements for each product on each of the four machines are shown in the table.

Work centers W, X, Y, and Z are available for 40 hours per week and have no setup time when switching between products. Market demand for each product is 80 units per week. In the questions that follow, the traditional method refers to maximizing the contribution margin per unit for each product, and the bottleneck method refers to maximizing the contribution margin per minute at the bottleneck for each product.

55) Use the information in Table 7.5. Which work center is of greatest concern to the operations manager?A) Work Center WB) Work Center XC) Work Center YD) Work Center ZAnswer: BReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: TOC, bottleneckAACSB: Analytic skills


56) Use the information in Table 7.5. Using the traditional method, which product should be scheduled first?A) Product AB) Product BC) Product CD) Product DAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck

57) Use the information in Table 7.5. Using the traditional method, in what sequence should products be scheduled for production?A) D, C, B, AB) D, B, A, CC) C, D, A, BD) C, D, B, AAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneck

58) Use the information in Table 7.5. Using the traditional method, what is the optimal product mix (consider variable costs only–overhead is not included in this profit calculation)?A) 71 A, 80B, 80C, 80 DB) 80A, 72B, 80C, 80DC) 80A, 80B, 60C, 80DD) 80A, 80B, 80C, 70DAnswer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

59) Use the information in Table 7.5. Using the traditional method, what is the profit if the company manufactures the optimal product mix (consider variable costs only–overhead is not included in this profit calculation)?A) less than or equal to $8,100B) greater than $8,100 but less than or equal to $8,300C) greater than $8,300 but less than or equal to $8,500D) greater than $8,500Answer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills


60) Use the information in Table 7.5. Using the bottleneck method, which product should be scheduled first?A) Product AB) Product BC) Product CD) Product DAnswer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck

61) Use the information in Table 7.5. Using the bottleneck method, in what sequence should products be scheduled for production?A) D. C. B. AB) D, C, A, BC) C, D, A, BD) C, D, B, AAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneck

62) Use the information in Table 7.5. Using the bottleneck method, what is the optimal product mix (consider variable costs only–overhead is not included in this profit calculation)?A) 71 A, 80B, 80C, 80 DB) 80A, 72B, 80C, 80DC) 80A, 80B, 60C, 80DD) 80A, 80B, 80C, 70DAnswer: AReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

63) Use the information in Table 7.5. Using the bottleneck method, what is the profit if the company manufactures the optimal product mix (consider variable costs only–overhead is not included in this profit calculation)?A) less than or equal to $8,100B) greater than $8,100 but less than or equal to $8,300C) greater than $8,300 but less than or equal to $8,500D) greater than $8,500Answer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills


Table 7.6Burdell Industries makes four different models of computer printers: the E-1000, the S-2000, the P-2000 and the N-1000. The E-1000 sells for $200 and has $40 in parts and $40 in labor; the S-2000 sells for $150 and requires $30 in parts and $30 in labor; the P-2000 sells for $100 and has $20 in parts and $20 in labor; and the N-1000 sells for $75 but requires only $10 of parts and $10 of labor. Fixed overhead is estimated at $5,000 per week. The manufacture of each printer requires four machines, Machines #1, 2, 3 and 4. Each of the machines is available for 40 hours a week and there is no setup time required when shifting from the production of one product to any other. The processing requirements to make one unit of each product are shown in the table. Weekly product demand for the next planning period has been forecasted as follows: 80 E-1000s; 65 S-2000s; 35 P-2000s; and 20 N-1000s.

In the questions that follow, the traditional method refers to maximizing the contribution margin per unit for each product, and the bottleneck method refers to maximizing the contribution margin per minute at the bottleneck for each product.

64) Use the information in Table 7.6. Which machine is the bottleneck operation?A) Machine 1B) Machine 2C) Machine 3D) Machine 4Answer: CReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: TOC, bottleneckAACSB: Analytic skills

65) Use the information in Table 7.6. Using the traditional method, which product should be scheduled first?A) Product EB) Product SC) Product PD) Product NAnswer: AReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneckAACSB: Analytic skills


66) Use the information in Table 7.6. Using the traditional method, in what sequence should products be scheduled for production?A) N, S, E, PB) N, E, P, SC) P, E, N, SD) E, S, P, NAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneckAACSB: Analytic skills

67) Use the information in Table 7.6. Using the traditional method, what is the optimal product mix?A) 120 E, 90 S, 60 P, 55 NB) 60 E, 20 S, 50 P, 33 NC) 80 E, 65 S, 35 P, 5 ND) 80 E, 65 S, 20 P, 35 NAnswer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

68) Use the information in Table 7.6. Using the traditional method, what is the profit if Burdell manufactures the optimal product mix?A) less than or equal to $10,000B) greater than $10,000 but less than or equal to $13,000C) greater than $13,000 but less than or equal to $16,000D) greater than $16,000Answer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mix, profitAACSB: Analytic skills

69) Use the information in Table 7.6. Using the bottleneck method, which product should be scheduled first?A) Product EB) Product SC) Product PD) Product NAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneckAACSB: Analytic skills


70) Use the information in Table 7.6. Using the bottleneck method, in what sequence should products be scheduled for production?A) N, S, E, PB) N, E, P, SC) P, E, N, SD) E, S, P, NAnswer: AReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneckAACSB: Analytic skills

71) Use the information in Table 7.6. Using the bottleneck method, what is the optimal product mix?A) 80 E, 65 S, 35 P, 20 NB) 60 E, 20 S, 50 P, 33 NC) 120 E, 90 S, 60 P, 55 ND) 80 E, 65 S, 30 P, 20 NAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

72) Use the information in Table 7.6. Using the bottleneck method, what is the profit if Burdell manufactures the optimal product mix?A) less than or equal to $10,000B) greater than $10,000 but less than or equal to $13,000C) greater than $13,000 but less than or equal to $16,000D) greater than $16,000Answer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mix, profitAACSB: Analytic skills


Table 7.7A company makes four products that have the following characteristics: Product A sells for $75 but needs $20 of materials and $20 of labor to produce; Product B sells for $90 but needs $45 of materials and $20 of labor to produce; Product C sells for $110 but needs $50 of materials and $30 of labor to produce; Product D sells for $135 but needs $75 of materials and $40 of labor to produce. The processing requirements for each product on each of the four machines are shown in the table.

Work centers W, X, Y, and Z are available for 40 hours per week and have no setup time when switching between products. Market demand is 50 As, 60 Bs, 70 Cs, and 80 Ds per week. In the questions that follow, the traditional method refers to maximizing the contribution margin per unit for each product, and the bottleneck method refers to maximizing the contribution margin per minute at the bottleneck for each product.

73) Use the information in Table 7.7. Which work center is the bottleneck operation?A) Work Center WB) Work Center XC) Work Center YD) Work Center ZAnswer: CReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: TOC, bottleneckAACSB: Analytic skills

74) Use the information in Table 7.7. Using the traditional method, which product should be scheduled first?A) Product AB) Product BC) Product CD) Product DAnswer: AReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneckAACSB: Analytic skills


75) Use the information in Table 7.7. Using the traditional method, in what sequence should products be scheduled for production?A) A, B, C, DB) A, C, B, DC) A, D, B, CD) D, B, C, AAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneckAACSB: Analytic skills

76) Use the information in Table 7.7. Using the traditional method, what is the optimal product mix?A) 37 A, 60 B, 70 C, 80 DB) 50 A, 51 B, 70 C, 80 DC) 50 A, 60 B, 62 C, 80 DD) 50 A, 60 B, 70 C, 60 DAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

77) Use the information in Table 7.7. Using the traditional method, what is the profit if the company manufactures the optimal product mix (consider variable costs only–overhead is not included in this profit calculation)?A) less than or equal to $6,500B) greater than $6,500 but less than or equal to $6,700C) greater than $6,700 but less than or equal to $6,900D) greater than $6,900Answer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

78) Use the information in Table 7.7. Using the bottleneck method, which product should be scheduled first?A) Product AB) Product BC) Product CD) Product DAnswer: AReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneckAACSB: Analytic skills

79) Use the information in Table 7.7. Using the bottleneck method, in what sequence should products be scheduled for production?A) A, D, B, CB) D, A, B, CC) A, D, C, BD) D, A, C, BAnswer: C


Reference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneckAACSB: Analytic skills

80) Use the information in Table 7.7. Using the bottleneck method, what is the optimal product mix? A) 37 A, 60 B, 70 C, 80 DB) 50 A, 51 B, 70 C, 80 DC) 50 A, 60 B, 62 C, 80 DD) 50 A, 60 B, 70 C, 60 DAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

81) Use the information in Table 7.7. Using the bottleneck method, what is the profit if the company manufactures the optimal product mix (consider variable costs only–overhead is not included in this profit calculation)?A) less than or equal to $6,500B) greater than $6,500 but less than or equal to $6,700C) greater than $6,700 but less than or equal to $6,900D) greater than $6,900Answer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills


Table 7.8King Supply makes four different types of plumbing fixtures: W, X, Y and Z. The contribution margins for these products are: $70 for Product W, $60 for Product X, $90 for Product Y and $100 for Product Z. Fixed overhead is estimated at $5,500 per week. The manufacture of each fixture requires four machines, Machines #1, 2, 3 and 4. Each of the machines is available for 40 hours a week and there is no setup time required when shifting from the production of one product to any other. The processing requirements to make one unit of each product are shown in the table. Weekly product demand for the next planning period has been forecasted as follows: 70 Ws, 60 Xs, 50 Ys and 30 Zs.

In the questions that follow, the traditional method refers to maximizing the contribution margin per unit for each product, and the bottleneck method refers to maximizing the contribution margin per minute at the bottleneck for each product.

82) Use the information in Table 7.8. Which machine is the bottleneck operation?A) Machine 1B) Machine 2C) Machine 3D) Machine 4Answer: AReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: TOC, bottleneckAACSB: Analytic skills

83) Use the information in Table 7.8. Using the traditional method, which product should be scheduled first?A) Fixture WB) Fixture XC) Fixture YD) Fixture ZAnswer: DReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneckAACSB: Analytic skills


84) Use the information in Table 7.8. Using the traditional method, in what sequence should the fixtures be scheduled for production?A) Z, Y, X, WB) X, W, Z, YC) Z, Y, W, XD) W, X, Y, ZAnswer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneckAACSB: Analytic skills

85) Use the information in Table 7.8. Using the traditional method, what is the optimal product mix?A) 70 W, 60 X, 90 Y, 100 ZB) 70 W, 50 X, 50 Y, 30 ZC) 70 W, 60 X, 47 Y, 30 ZD) 70 W, 47 X, 50 Y, 30 ZAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

86) Use the information in Table 7.8. Using the traditional method, what is the profit if King Supply manufactures the optimal product mix?A) less than or equal to $10,000B) greater than $10,000 but less than or equal to $11,000C) greater than $11,000 but less than or equal to $12,000D) greater than $12,000Answer: AReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mix, profitAACSB: Analytic skills

87) Use the information in Table 7.8. Using the bottleneck method, which product should be scheduled first?A) Fixture WB) Fixture XC) Fixture YD) Fixture ZAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneckAACSB: Analytic skills


88) Use the information in Table 7.8. Using the bottleneck method, in what sequence should products be scheduled for production?A) Z, Y, X, WB) X, W, Z, YC) Z, Y, W, XD) X, Y, Z, WAnswer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, sequence, profit per minute at bottleneckAACSB: Analytic skills

89) Use the information in Table 7.8. Using the bottleneck method, what is the optimal product mix?A) 70 W, 60 X, 90 Y, 100 ZB) 70 W, 50 X, 50 Y, 30 ZC) 70 W, 60 X, 47 Y, 30 ZD) 70 W, 47 X, 50 Y, 30 ZAnswer: CReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mixAACSB: Analytic skills

90) Use the information in Table 7.8. Using the bottleneck method, what is the profit if Burdell manufactures the optimal product mix?A) less than or equal to $10,000B) greater than $10,000 but less than or equal to $11,000C) greater than $11,000 but less than or equal to $12,000D) greater than $12,000Answer: BReference: Identification and Management of BottlenecksDifficulty: HardKeywords: TOC, bottleneck, profit per minute at bottleneck, mix, profitAACSB: Analytic skills

91) In a drum-buffer-rope system, the lot size that moves from one work center to another for additional processing is a(n):A) process batch.B) operations batch.C) transfer batch.D) rope batch.Answer: CReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: DBR, drum-buffer-rope, transfer batch


92) The process batch at the constraint in a drum-buffer-rope system should be:A) the same size as that at any non-constraint.B) the same size as the transfer batch.C) of such a size as to maximize the number of setups for the constraintD) of such a size as to improve utilization of the constraint.Answer: DReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: DBR, drum-buffer-rope, process, batch, size

93) Which one of the following statements is best concerning line balancing?A) The theoretical minimum number of stations must always be fewer than the actual number achieved in a final solution. Increasing the output rate may increase the theoretical minimum number of stations.B) The "largest number of followers" rule assigns as quickly as possible those work elements most difficult to fit into a station.C) Selecting the cycle time can never have an effect on line efficiency.Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balancing, output rate, theoretical minimum number of work stationsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

94) What is the definition of "theoretical maximum efficiency"?A) It is the amount by which efficiency falls short of 100 percent.B) It is the efficiency that could be obtained by a solution that achieves the theoretical minimum number of stations.C) It is the maximum time allowed for work on a unit at each station.D) It is alternatively called the desired output rate.Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process

95) Balance delay could be described as the:A) amount by which efficiency falls short of 100 percent.B) efficiency that could be obtained by a solution that achieves the theoretical minimum number of stations.C) maximum time allowed for work on a unit at each station.D) desired output rate.Answer: AReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: balance delay, line process


96) A line balance that is 100% efficient must:A) be using the minimum cycle time.B) be using the theoretical minimum number of work stations.C) also achieve 100% balance delay.D) be producing the theoretical maximum output.Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process

97) Instead of dividing by nc to determine the efficiency of a line balance, you could divide by:A) the number of workers times the number of stations.B) the number of tasks plus the number of stations.C) the sum of the task times plus the sum of the idle times.D) (1-balance delay).Answer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process

98) The most controversial aspect of line-flow layout is:A) the heuristic decision rules in assigning the next work element.B) the number of models produced.C) the cycle time.D) behavioral response.Answer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: behavioral response, line process

99) A line that produces several items belonging to the same family is called a:A) mixed-model line.B) part family line.C) group technology line.D) cellular line.Answer: AReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: mixed-model, line process


100) Which one of the following statements about line balancing is best?A) If a precedence relationship exists between A and B, they cannot be assigned to the same station.B) If the desired output rate increases, the cycle time also tends to increase.C) The theoretical minimum number of stations can never be achieved, hence the name "theoretical."D) If a line's balance delay is minimized, its efficiency is maximized.Answer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balancing, flow, balance delay, efficiencyLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

Figure 7.1

101) Use the information in Figure 7.1. What are the required predecessors of activity H?A) E & GB) A through F, including EC) Activity H has no required predecessors.D) DAnswer: AReference: Managing Constraints in a Line ProcessDifficulty: EasyKeywords: predecessor, line process, flow

102) Use the information in Figure 7.1. If each task has a work time of one minute, what is the theoretical minimum cycle time?A) There is no minimum cycle time.B) 1 minuteC) 8 minutesD) The cycle time cannot be determined with the information given.Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: cycle time, line process, flowAACSB: Analytic skills


103) Use the information in Figure 7.1. If each task has a work time of one minute and there are 480 work minutes in a day, what is the task assignment at the fourth workstation if maximum output is desired?A) AB) BC) CD) DAnswer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: cycle, line process, flow, taskAACSB: Analytic skills

104) Use the information in Figure 7.1. If each task has a work time of one minute and there are 8 hours in a day, what is the task assignment at the first station if 160 units should be produced each day?A) A, B, C, DB) H, G, F, EC) A, B, CD) H, G, FAnswer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line process, flow, task, stationAACSB: Analytic skills

105) Use the information in Figure 7.1. If each task has a work time of one minute and there are 8 hours in a day, what is the minimum number of stations if 240 units should be produced each day?A) oneB) twoC) threeD) fourAnswer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: station, minimum number of stationsAACSB: Analytic skills


Table 7.9Balance the following line for an output rate of 3 units per minute.

Work Element

Time (sec)

Immediate Predecessor(s

)A 12 --B 6 AC 12 AD 4 BE 14 B, CF 10 EG 6 D, F

106) Use the information in Table 7.9. How many stations are required?A) 3B) 4C) 5D) 6Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: stations, flow, line processAACSB: Analytic skills

107) Use the information in Table 7.9. What is the balance delay for your solution?A) less than or equal to 15%B) more than 15% but less than or equal to 25%C) more than 25% but less than or equal to 35%D) more than 35%Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: balance delay, line process, flowAACSB: Analytic skills


Table 7.10Balance the following line for an output rate of five pieces per hour. The times are in minutes (not seconds).

Work Element

Time (min)


)A 7 --B 5 --C 3 --D 4 --E 2 A, BF 5 CG 6 DH 7 E, FI 11 F, GJ 4 H, I

108) Use the information from Table 7.10. The theoretical minimum number of stations is:A) fewer than three stations.B) three stations.C) four stations.D) more than four stations.Answer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line process, flow, stationsAACSB: Analytic skills

109) Use the information from Table 7.10. The highest efficiency for a balanced line is:A) less than 89%.B) more than 89% and less than 91%.C) more than 91% and less than 93%.D) more than 93%.Answer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line process, flow, efficiencyAACSB: Analytic skills


Table 7.11The Pennsylvania Appliance Company is installing an assembly line to produce vacuum cleaners, and you, as an operations manager, are responsible for balancing the line. The work elements to be performed are listed, along with their times and immediate predecessors.

Work Element

Time (sec)


)A 60 --B 40 AC 30 BD 20 BE 40 BF 60 CG 70 DH 50 F, GI 20 EJ 60 H, I

110) Use the information in Table 7.11. The company is planning to operate 2 shifts per day, 8 hours per shift. If the desired output rate of the line is 480 units per day, what is the cycle time?A) 60 secondsB) 120 secondsC) 180 secondsD) 240 secondsAnswer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: cycle time, line process, flowAACSB: Analytic skills

111) Use the information in Table 7.11. The company is planning to operate 2 shifts per day 8 hours per shift. If the desired output rate of the line is 480 units per day, what is the theoretical minimum number of stations (TM) for the line? How many workstations are needed for the most efficient balance possible given these circumstances?A) TM = 3; solution = 3 stationsB) TM = 3; solution = 4 stationsC) TM = 4; solution = 4 stationsD) TM = 4; solution = 5 stationsAnswer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: stations, line process, flowAACSB: Analytic skills


112) Use the information in Table 7.11. The company is planning to operate 2 shifts per day 8 hours per shift. If the desired output rate of the line is 480 units per day, what is the highest efficiency possible for a balanced line?A) less than 91%B) more than 91% and less than 93%C) more than 93% and less than 95%D) more than 95%Answer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process, flowAACSB: Analytic skills

Table 7.12A company desires to set up a line to produce 60 units per hour. The work elements and their precedence relationships are as follows.

Work Element Time (sec)

Immediate Predecessor

(s)1 40 -2 30 13 50 14 40 25 6 26 25 37 15 38 20 4, 59 18 6, 7

10 30 8, 9

113) Use the information in Table 7.12. What is the theoretical minimum number of stations?A) 3B) 4C) 5D) 6Answer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: minimum number of stations, line process, flowAACSB: Analytic skills


114) Use the information in Table 7.12. What is the highest efficiency line balance possible?A) less than 93%B) more than 93% but less than or equal to 95%C) more than 95% but less than or equal to 97%D) more than 97%Answer: AReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process, flowAACSB: Analytic skills

Table 7.13The following information is given about an assembly line. The desired output rate is 90 units per hour.

Work Element

Time (sec)


)A 10 --B 6 AC 15 AD 20 BE 12 BF 14 C, EG 8 DH 20 F, G

115) Use the information in Table 7.13. What is the fewest number of workstations that you need?A) two stationsB) three stationsC) four stationsD) more than four stationsAnswer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: minimum number of stations, line process, flowAACSB: Analytic skills

116) Use the information in Table 7.13. Suppose that the desired output rate is increased to 120 units per hour and a solution has been found that has four workstations. What is the efficiency of this new assembly line?A) less than 80%B) between 80% and 85%C) between 85% and 90%D) more than 90%Answer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process, flowAACSB: Analytic skills

117) A line-balancing solution has been developed for the assembly line for fertilizer spreaders at Green Grass, Inc. The desired output rate of 30 spreaders per hour will be achieved. The sum of times for all tasks performed on the line is 1200 seconds for each


spreader assembled. This is the total productive time. Which of the following statements must be true?A) The cycle time is 30 seconds per spreader.B) The theoretical minimum number of stations is 10.C) If the solution calls for 11 stations, the efficiency is 80%.D) If the solution calls for 12 stations, the efficiency is 80%.Answer: BReference: Managing Constraints in a Line ProcessDifficulty: Moderate

Table 7.14The production of a particular product consists of seven work elements. The desired output rate is 60 units per hour. The work element and their precedence relationships are given.

Work Element

Time(sec)


)1 30 --2 15 13 20 24 15 35 30 36 25 47 30 5, 6

118) Use the information in Table 7.14. How many stations are required for the most efficient balance you can achieve?A) two stationsB) three stationsC) four stationsD) five stationsAnswer: BReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line process, flow, minimum number of stationsAACSB: Analytic skills

119) Use the information in Table 7.14. What is the most efficient line balance you can achieve?A) less than or equal to 70%B) more than 70% but less than or equal to 75%C) more than 75% but less than or equal to 80%D) more than 80%Answer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process, flowAACSB: Analytic skills

120) An assembly line has to perform 10 work elements, whose time requirements follow. An operations analyst has found a solution using some heuristics, as shown in the table. If the cycle time of the line is 90 seconds, what is the efficiency of the assembly line?


A) less than 85%B) greater than 85% but less than 90%C) greater than 90% but less than 95%D) greater than 95%Answer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: efficiency, line process, flowAACSB: Analytic skills


121) Given the following data about an assembly line and the knowledge that we are trying to attain an output rate of 40 units per hour, what is the theoretical minimum number of stations?

Work Element Time (sec)

1 902 803 754 705 906 85

A) four or fewer stationsB) five stationsC) six stationsD) seven or more stationsAnswer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line process, flow, minimum number of stationsAACSB: Analytic skills

122) The production of a particular product consists of the following work elements. If the cycle time is 4 minutes and the work-element times are as follows, what is the theoretical minimum number of stations?

Work Element

Time (min)

1 2.42 0.53 2.14 2.05 2.76 1.17 2.08 2.79 1.6

10 1.4

A) fewer than or equal to three stationsB) four stationsC) five stationsD) more than five stationsAnswer: CReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line process, flow, minimum number of stationsAACSB: Analytic skills

123) Fun Vehicles, Inc. makes beach buggies on an assembly line. The total productive time to make one buggy is 300 seconds. The current line has a 90-second cycle time and consists of four workstations. The balance delay of this line must be:A) 0%.B) greater than 0% but less than 6%.


C) greater than 6% but less than 12%.D) greater than 12% but less than 18%.Answer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: balance delay, line process, flowAACSB: Analytic skills

Table 7.15The Terminal Company is attempting to balance its assembly line of high-voltage electrical connectors. The desired output for the line is 50 connectors per hour, and the information on the work elements for this assembly line is as follows.

Work Elements Time (sec)


)A 40 --B 36 AC 20 AD 25 AE 30 B, CF 34 DG 35 EH 5 FI 15 E, HJ 40 HK 38 G, I, J

124) Use the information from Table 7.15 to balance this line. What is the most efficient solution?A) more than 90%B) 80 - 90%C) 70 - 79%D) less than 70%Answer: CReference: Managing Constraints in a Line ProcessDifficulty: HardKeywords: efficiency, line balance, flowAACSB: Analytic skills


125) Use the information from Table 7.15 and the most efficient line balance possible. What work elements are included in the first station?A) A onlyB) A and B onlyC) A and E onlyD) A and D onlyAnswer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: tasks, station, line balance, flowAACSB: Analytic skills

126) Use the information from Table 7.15, and assume that the most efficient line balance possible ha been achieved. What is the total idle time for an eight hour work day?A) less than an hour and a halfB) more than 1:30 but less than or equal to 1:45C) more than 1:45 but less than or equal to 2 hoursD) more than 2 hoursAnswer: DReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: idle time, line balance, flowAACSB: Analytic skills

127) Any factor that limits the performance of a system and restricts its output is a(n) ________.Answer: constraintReference: IntroductionDifficulty: EasyKeywords: constraint

128) ________ is the maximum rate of output of a process or a system.Answer: CapacityReference: IntroductionDifficulty: EasyKeywords: capacity

129) A(n) ________ is an operation that has the lowest effective capacity of any operation in the process, and thus limits the system's output.Answer: bottleneckReference: The Theory of ConstraintsDifficulty: EasyKeywords: bottleneck, TOC, output


130) According to the Theory of Constraints, all the money invested in a system in purchasing things that it intends to sell is ________.Answer: inventoryReference: The Theory of ConstraintsDifficulty: EasyKeywords: inventory, TOC

131) According to the Theory of Constraints, brand new cars on the lot waiting to be sold are ________, not ________.Answer: inventory, throughputReference: The Theory of ConstraintsDifficulty: EasyKeywords: inventory, TOC, throughput

132) The wages paid to workers on the line are categorized as ________ in the Theory of Constraints.Answer: operational expenseReference: The Theory of ConstraintsDifficulty: EasyKeywords: operational expense

133) ________ is the total time taken from the start to the finish of a process.Answer: Throughput timeReference: Identification and Management of BottlenecksDifficulty: EasyKeywords: throughput time

134) Variability of a firm's workload may create ________.Answer: floating bottlenecksReference: Identification and Management of BottlenecksDifficulty: HardKeywords: workload, variability, floating bottleneck

135) With TOC, ________ are scheduled to maximize their throughput of products while adhering to promised completion dates.Answer: bottlenecksReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: TOC, bottleneck

136) Instead of producing products with the highest profit margins, operations managers should focus on the ________ generated at the ________ .Answer: profit (margin), bottleneckReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: TOC, bottleneck, profit, profit marginLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

137) ________ is a planning and control system that regulates the flow of work-in-process materials at the bottleneck or the capacity constrained resource in a productive system.Answer: Drum-buffer-rope (DBR)Reference: Identification and Management of BottlenecksDifficulty: EasyKeywords: drum-buffer-rope, DBR, CCR, capacity constrained resource, bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in


service and manufacturing processes.

138) Every time a manufacturer uses one resource, they make a lot size of 300. Once a group of 30 units are completed, they are taken to the next step in the process. The lot of 300 is the ________ and the group of 30 is the ________.Answer: production batch, transfer batchReference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: production batch, transfer batch

139) ________ is the maximum time allowed for work on a unit at each station.Answer: Cycle timeReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: cycle time, work, line process, flow

140) ________ is the amount by which efficiency falls short of 100 percent.Answer: Balance delayReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: balance delay, efficiency, line process, flow

141) Regardless of the number of tasks or their lengths, a line balance efficiency of 100% is possible if the number of stations is ________.Answer: oneReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balance, efficiency

142) A(n) ________ line is a product line that produces several items belonging to the same family.Answer: mixed-modelReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: mixed-model line, family

143) The movement of product from one station to the next as soon as the cycle time has elapsed is called ________.Answer: pacingReference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: pacing, line process, flow, cycle time

144) Explain why a bottleneck limits system output.Answer: A bottleneck, by definition, is a process that has less capacity than all other processes in the system. Just as a chain is as strong as its weakest link, the rest of a production system can produce only as much as the slowest process. The bottleneck limits capacity by serving to slow the rest of the system down. Running all other processes at their maximum capacity will result in inventory buildup in front of the bottleneck.Reference: IntroductionDifficulty: ModerateKeywords: bottleneck, output, TOCLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

145) What are five of the seven key principles of the Theory of Constraints?


Answer: The principles of TOC areThe focus should be on balancing flow, not on balancing capacity.Maximizing the output and efficiency of every resource may not maximize the throughput of the entire system.An hour lost at a bottleneck or a constrained resource is an hour lost for the whole system. In contrast, an hour saved at a nonbottleneck resource is a mirage because it does not make the whole system more productive.Inventory is needed only in front of the bottlenecks in order to prevent them from sitting idle, and in front of assembly and shipping points in order to protect customer schedules. Building inventories elsewhere should be avoided.Work, which can be materials, information to be processed, documents, or customers, should be released into the system only as frequently as the bottlenecks need it. Bottleneck flows should be equal to the market demand. Pacing everything to the slowest resource minimizes inventory and operating expenses.Activating a nonbottleneck resource (using it for improved efficiency that does not increase throughput) is not the same as utilizing a bottleneck resource (that does lead to increased throughput). Activation of nonbottleneck resources cannot increase throughput, nor promote better performance on financial measures outlined in Table 7.1.Every capital investment must be viewed from the perspective of its global impact on overall throughput (T), inventory (I), and operating expense (OE).Reference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, stepsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.


146) Describe a process from your own personal experience at home or work that suffers from a lack of sufficient throughput. Apply the first four TOC steps to address the situation, assuming you have complete authority to do so.Answer: Examples will vary. The steps of TOC are (1) identify the system bottleneck(s); (2) exploit the bottlenecks; (3) subordinate all other decisions to step 2; (4) elevate the bottleneck(s); and (5) do not let inertia set in.Reference: The Theory of ConstraintsDifficulty: ModerateKeywords: TOC, stepsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

147) What are two ways a process manager can identify a bottleneck in a service or manufacturing process? If you were in a manufacturing firm, what physical cues would signal a bottleneck?Answer: A workstation in a process is a bottleneck if 1) it has the highest total time per unit processed, or 2) it has the highest average utilization and total workload. Generally, the bottleneck has a pile of materials in front of it waiting to be processed.Reference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

148) What is contribution margin for a product? How might it be used to manage the productive resources on a shop floor?Answer: Contribution margin is the amount each product contributes to profits and overhead. Determining which product has the highest contribution margin and producing it at the expense of other products is the traditional method of shop floor management. The Theory of Constraints instead studies product's contribution margin based on bottleneck usage, which may be entirely different.Reference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.


149) What is a Drum-Buffer-Rope system for planning and control?Answer: Drum-Buffer-Rope (DBR) is a planning and control system based on the theory of constraints that is often used in manufacturing firms to plan and schedule production. It works by regulating the flow of work-in-process materials at the bottleneck or the capacity constrained resource (CCR). The bottleneck schedule is the drum because it sets the beat or the production rate for the entire plant and is linked to the market demand. The buffer is a time buffer that plans early flows to the bottleneck and thus protects it from disruption. It also ensures that the bottleneck is never starved for work. A finished-goods inventory buffer can also be placed in front of the shipping point in order to protect customer shipping schedules. Finally, the rope represents the tying of material release to the drum beat, which is the rate at which the bottleneck controls the throughput of the entire plant. It is thus a communication device to ensure that raw material is not introduced into the system at a rate faster than what the bottleneck can handle. Completing the loop, buffer management constantly monitors the execution of incoming bottleneck work. Working together, the drum, the buffer, and the rope can help managers create a production schedule that reduces lead times and inventories while simultaneously increasing throughput and on-time delivery.Reference: Identification and Management of BottlenecksDifficulty: ModerateKeywords: bottleneckLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

150) Describe three ways that line balancing and line flow layouts are similar to project management and three ways they are different.Answer: Answers may vary. Line balancing and project management both rely on the completion of predefined activities in the proper sequence. A line flow may have multiple feeder lines that supply subassemblies to the main line, similar to subcontractors working on the project in state of partial completion. Both have anticipated completion times that may not be reached if things don't go smoothly.

The time scale is radically different between line balancing and project management; projects tend to take much longer. Projects also tend to be one of a kind endeavors; line balancing is performed with the anticipation of high volumes of fairly standardized output. Line flows are created for more routine, process-oriented work that can be composed of standardized tasks. Projects are typically anything but routine and far from process-focused.Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balancing, flow layoutLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.


151) You have been assigned a line balancing task and given a list of tasks, their precedence requirements, and the time needed to accomplish them. As you begin to balance the line, you realize that you must make some assumptions. What are these assumptions and which of them has the greatest impact on the success of your balance?Answer: One assumption that is being made is that the task times are invariant, unless a mean and standard deviation have both been provided. You must also assume that the task durations will stay roughly the same, i.e., that learning effects are not significantly different amongst the tasks. You are also assuming that the tasks will stay somewhat static, or the line would require rearrangement and possibly rebalancing with some frequency. You also assume that the precedence is static. Among these, the last assumption is probably the least tenuous.Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balancing, flow layoutLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.

152) How can Theory of Constraints principles be reconciled with line balancing?Answer: Line balancing strives to assign work to stations such that the amount of work at each station is equal. Work flows from station to station based on a cycle time that is determined based on the number of units to be produced per unit time. Theory of Constraints stresses the need to balance flow with demand and is concerned with preserving flow through the bottleneck, or lowest capacity station. Flow can be preserved by protecting the bottleneck with protective WIP and making sure that market demand is sufficient to support continuous bottleneck operation. Line balancing, as explained in the text, assumes that all task times are constant. So the person performing the balance can try to allocate capacity as evenly as possible. If task times were stochastic, then flow would not be preserved with classic line balancing techniques because the lowest capacity work station would occasionally fall idle.Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balancing, TOC, theory of constraintsLearning Outcome: Explain options for managing bottlenecks and managing capacity in service and manufacturing processes.


153) Schmidt Industries makes four different snake traps; the Harlan, the Gaylen, the Leah and the Matthew. The Harlan sells for $200 and has $40 in parts and $40 in labor; the Gaylen sells for $150 and requires $30 in parts and $30 in labor; the Leah sells for $100 and has $20 in parts and $20 in labor; and the Matthew sells for $75 but requires only $10 of parts and $10 of labor. Schmidt Industries has four machines (we'll call them A, B, C, and D for convenience) that are used in the production of each of these products. Each of these machines is available for 40 hours a week and there is no setup time required when shifting from the production of one product to any other. The processing requirements to make one unit of each product are shown in the table.

Schmidt Industries has monthly fixed costs of $5000 and has a demand forecast of 80 Harlans, 60 Gaylens, 40 Leahs and 20 Matthews for the coming month. How many of each of the four models should Susan, the operations manager, schedule for production this month?Answer: The processing requirements for the demand forecast result in a need for:

Machine A: 80 × 10 + 60 × 10 + 40 × 5 + 20 × 5 = 1700 ≤ 2400Machine B: 80 × 15 + 60 × 10 + 40 × 10 + 20 × 10 = 2300 ≤ 2400Machine C: 80 × 15 + 60 × 10 + 40 × 15 + 20 × 10 = 2500 ≰ 2400 BottleneckMachine D: 80 × 5 + 60 × 10 + 40 × 10 + 20 × 10 = 1600 ≤ 2400

The contribution margin per bottleneck minute is:

Harlan: (200 - 40 - 40)/15 = $8/minGaylen: (150 - 30 - 30)/10 = $9/minLeah: (100 - 20 - 20)/15 = $4/minMatthew: (75 - 10 - 10)/5 = $11/min

Products should be produced in Matthew, Gaylen, Harlan, and Leah order. The product mix is 20 Matthews (using 100 minutes of Machine C); 60 Gaylens (using 600 minutes of Machine C); 80 Harlans (using 1200 minutes of Machine C); and 33 Leahs (using up the remaining 500 minutes of Machine C time).Reference: Identification and Management of BottlenecksDifficulty: HardKeywords: capacity, bottleneckAACSB: Analytic skills


154) Consider the process shown that is trying to produce to meet a market demand of 500 units per week.

Step 1: Material release scheduleStep 2: Drilling (capacity is 500 units/week)Step 3: Tapping (capacity is 450 units/week)Step 4: Grinding (capacity is 600 units/week)Step 5: Coating (capacity is 400 units/week)Step 6: Inspection (capacity is 1000 units/week)

a. Where should buffers be placed?b. Which resource is the drum?c. Where should the rope be placed?d. Which resource is the bottleneck?e. Which resource is the CCR?Answer: a. A constraint buffer should be placed between steps 4 and 5 to protect the bottleneck which is Step 5 (Coating). A shipping buffer should be placed at the end of the line, after Step 6, (Inspection).b. The resource functioning as the drum is the bottleneck, Step 5.c. The rope should connect Step 1 and Step 5.d. The bottleneck is Step 5.e. A CCR exists if the process with the least capacity can still meet market demand, which is not the case in this scenario.Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: drum-buffer-rope, DBR, CCR, capacity constraint resource, bottleneckAACSB: Analytic skills


155) Consider the process shown that is trying to produce to meet a market demand of 250 units per week.

Step 1: Material release scheduleStep 2: Drilling (capacity is 300 units/week)Step 3: Tapping (capacity is 150 units/week)Step 4: Grinding (capacity is 300 units/week)Step 5: Coating (capacity is 200 units/week)Step 6: Inspection (capacity is 500 units/week)

a. Where should buffers be placed?b. Which resource is the drum?c. Where should the rope be placed?d. Which resource is the bottleneck?e. Which resource is the CCR?Answer: a. A constraint buffer should be placed between steps 2 and 3 to protect the bottleneck which is Step 3 (Tapping). A shipping buffer should be placed at the end of the line, after Step 6, (Inspection).b. The resource functioning as the drum is the bottleneck, Step 3.c. The rope should connect Step 1 and Step 3.d. The bottleneck is Step 3.e. A CCR exists if the process with the least capacity can still meet market demand, which is not the case in this scenario.Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: drum-buffer-rope, DBR, CCR, capacity constraint resource, bottleneckAACSB: Analytic skills


156) Balance the assembly line for the tasks contained in the table. The desired output is 240 units per day. Available production time per day is 480 minutes. What is the efficiency for the balanced assembly line?

Work Element Time (Sec.)


)A 40 ---B 45 ---C 55 AD 55 BE 65 BF 40 C, DG 25 D, E

Answer: For 240 units/day with available time of 480 minutes per day, the cycle time is 2.00 minutes or 120 seconds.One line balance is:

Station 1 2 3 TotalsTask(s) B, E D, A C, F, GWork Time 45, 65 55, 40 55, 40, 25 325Idle Time 10 25 0 35

Efficiency = = = 90.28%

There are four other legal assignments possible at the first work station, AB, BA, AC, and BD. There are a large number of possible legal balances since the longest two task times sum to 120, which is within the desired cycle time. A number of possible balances will achieve the three station balance that yields 90.28% efficiency.Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balance, efficiencyAACSB: Analytic skills


157) Balance the assembly line for the tasks contained in the table. The desired output is three units per hour. Available production time per day is eight hours. What is the theoretical minimum number of stations? What is the efficiency for the balanced assembly line?

Work Element Time (Min.)


)A 5 ---B 8 AC 12 AD 11 BE 5 CF 6 DG 4 DH 12 EI 14 G, HJ 9 FK 8 IL 3 K, J

Answer: For 3 units/hour the cycle time is 20 minutes.The theoretical minimum number of stations is 97/20=4.85→5One line balance is:

Station 1 2 3 4 5 6 TotalsTask(s) A, C B, D F, J, E H, G I K, LWork Time 5, 12 8, 11 6, 9, 5 12, 4 14 8, 3 97Idle Time 3 1 0 4 6 9 23


Reference: Managing Constraints in a Line ProcessDifficulty: ModerateKeywords: line balance, efficiencyAACSB: Analytic skills


158) Balance the assembly line using the following task information contained in the table. The desired output is 360 units per day. Available production time per day is 480 minutes. What is the efficiency for the balanced assembly line?

Work Element Time (Sec.)


)A 30 ---B 20 AC 50 AD 45 BE 30 BF 55 C, DG 35 D, EH 40 F

Answer: Cycle time for 360 units in a 480 minute day is 480/360 = 1.33 minutes = 80 secondsThe theoretical minimum number of stations is 4; this balance is one of the 5-station solutions.

Station 1 2 3 4 5 TotalsTask(s) A, C B, D F H, E GWork Time 30, 50 20, 45 55 40, 30 35 305Idle Time 0 15 25 10 45 95




159) Balance the line in order to achieve maximum output for this ten activity product. Determine the number of units produced in a seven hour work day and the total idle time in hours.

Task Time (sec) PredecessorZ 40 ---Y 30 ZX 80 ZW 75 X, YV 15 WT 55 WS 35 VR 40 TQ 10 RM 40 S, R

Answer: Cycle time for maximum output is 80 seconds and the theoretical minimum number of stations is

Station 1 2 3 4 5 6 7 TotalsTask(s) Z, Y X W V, T S R, M QWork Time 40, 30 80 75 15, 55 70 40, 40 60 420Idle Time 10 0 5 10 10 0 20 55


There are 315 units produced in a day.

The total idle time per day at this level of production is 4.8125 hours. (4:48:45 to be precise)

300 units/day × 55 seconds idle/unit = 17,325 seconds

= 4.8125 hours



160) Balance the line in order to achieve maximum output for this eight-activity product. Then balance the line to maximize the efficiency of the operation. How do the levels of output (assume an eight hour day) and line efficiencies compare?

Task Time (min) Predecessor1 10 ---2 8 Task 13 9 Task 14 2 Task 25 6 Task 3

6 12Task 4, Task

57 7 Task 5

8 5Task 6, Task

7

Answer: The cycle time for maximum output is 12 minutes. One balance is show below; it has 6 stations, an increase of one from the theoretical minimum of five stations. It produces at 81.9% efficiency. It produces a unit every twelve minutes, so over the course of a day it can produce 40 units using six people.

Station 1 2 3 4 5 6 TotalsTask(s) 1 3 2, 4 5 6 7, 8Work Time 10 9 8, 2 6 12 7, 5 59Idle Time 2 3 2 6 0 0 13


The cycle time for maximum efficiency is 59 minutes. One balance is show below; it has one station and produces at 100% efficiency. It produces a unit every 59 minutes, so over the course of an eight-hour day it can produce eight complete units plus get started on a ninth unit using just one person. If the line was replicated and six workers perfectly cross trained, they could produce 54 units and start on the first task for units 55-60.

Station 1 TotalsTask(s) 1, 3, 2, 4, 5, 6, 7, 8

Work Time10, 9, 8, 2, 6, 12, 7, 5 59

Idle Time 0 0

Efficiency = = = 100%



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