Deck 14: Short-Term Scheduling

Question 1

Which of the following is NOT a key direct benefit from effective internal or external scheduling?

A) lower cost
B) greater use of assets
C) more dependable delivery
D) higher quality
E) added flexibility

Answer 1

D

Question 2

What is the objective of scheduling?

A) maximize quality
B) minimize cost
C) minimize response time
D) prioritize and allocate demand to available facilities
E) minimize lead time

Answer 2

D

Question 3

Which of the following statements regarding scheduling at Alaska Airlines is FALSE?

A) Flying into Alaska complicates scheduling.
B) Schedule changes at one airport have a ripple effect that may have impacts in many others.
C) Alaska Airlines' high-tech computer and communications system is located in Seattle.
D) Alaska Airlines' rapid rescheduling uses mathematical scheduling models.
E) Alaska Airlines' rapid rescheduling promotes air safety and limits traveler inconvenience, but it has not resulted in money savings for Alaska Airlines.

Answer 3

E

Question 4

The correct sequence from longest to smallest duration scheduling is:

A) capacity planning, aggregate planning, master schedule, short-term scheduling.
B) aggregate planning, capacity planning, master schedule, short-term scheduling.
C) master schedule, capacity planning, aggregate planning, short-term scheduling.
D) master schedule, aggregate planning, capacity planning, short-term scheduling.
E) capacity planning, master schedule, aggregate planning, short-term scheduling.

Question 5

Alaska Airlines uses mathematical short-term scheduling techniques and a high-tech Flight Operations Department to manage the rapid rescheduling necessary to cope with weather delays and similar disruptions.

Question 6

Techniques that load work without regard for the capacity of the process are:

A) aggregate planning.
B) backward scheduling.
C) forward scheduling.
D) finite loading.
E) infinite loading.

Question 7

Short-term schedules are prepared:

A) directly from the aggregate plans.
B) directly from the capacity plans.
C) from inventory records for items that have been used up.
D) from master schedules, which are derived from aggregate plans.
E) from the purchasing plans.

Question 8

What makes short-term scheduling of strategic importance?

Question 9

The short-term scheduling activity called "loading":

A) assigns dates to specific jobs or operations steps.
B) specifies the order in which jobs should be done at each center.
C) assigns jobs to work centers.
D) assigns workers to jobs.
E) assigns workers to machines.

Question 10

Forward scheduling is used in manufacturing environments, as well as service environments such as catering a banquet or scheduling surgery.

Question 11

Which of the following considers process capacity when scheduling?

A) cap loading
B) constrained loading
C) capacitated loading
D) backward loading
E) finite loading

Question 12

Briefly describe how "the unexpected" makes short-term scheduling at Alaska Airlines a challenge. Also describe how Alaska Airlines meets that challenge and achieves competitive advantage through short-term scheduling.

Question 13

Short-term scheduling is important to efficiency and to cost reduction, but its impact is not of strategic importance.

Question 14

One criterion for developing effective schedules is maximizing completion time.

Question 15

Process-focused facilities and repetitive facilities generate forward-looking schedules, but process-focused facilities do this with JIT and kanban while repetitive facilities generally use MRP.

Question 16

Forward scheduling is the scheduling of:

A) the end items or finished products.
B) jobs as soon as the requirements are known.
C) the start items or component parts.
D) the final operation first beginning with the due date.
E) jobs according to their profit contributions.

Question 17

The benefits of effective scheduling include lower cost, faster throughput, and dependable delivery.

Question 18

Forward scheduling:

A) begins with a delivery date, then offsets each operation one at a time, in reverse order.
B) has the same meaning as "finite loading."
C) is often used in service environments such as catering a banquet or scheduling surgery.
D) starts the schedule as soon as the job requirements are known.
E) produces a schedule only if it meets the due date.

Question 19

With forward scheduling, jobs are scheduled as late as possible within the time allowed by the customer due dates.

Question 20

Which of the following is NOT an effectiveness criterion for scheduling?

A) minimizing customer waiting time
B) minimizing completion time
C) minimizing WIP inventory
D) maximizing utilization
E) maximizing flow time

Question 21

What is a scheduling technique used to achieve an optimum, one-to-one matching of tasks and resources?

A) the assignment method
B) Johnson's rule
C) the CDS algorithm
D) the appointment method
E) the reservation method

Question 22

One of the major limitations of the Gantt load chart is that it doesn't account for production variability such as unexpected breakdowns or human errors.

Question 23

Compare short-term scheduling at process-focused, repetitive, and product-focused facilities.

Question 24

The constant work-in-process (ConWIP) card aids input-output control by limiting the amount of work in a work center.

Question 25

A Gantt load chart shows the loading and idle time of several departments, machines, or facilities.

Question 26

The assignment method provides an optimum, one-to-one assignment of jobs to resources.

Question 27

Explain, in your own words, how backward scheduling and forward scheduling differ.

Question 28

In the sequence of decisions that affect scheduling, ________ is (are) the immediate follower(s) of the master schedule (or master production schedule).

Question 29

Gantt charts are useful for scheduling jobs, but not for loading them.

Question 30

A work center had actual input of 280 hours and actual output of 290 hours. What is the change in backlog?

A) 10
B) -10
C) 0
D) 1.037
E) Unable to determine with the given information

Question 31

There are two jobs to be assigned to two workers. The cost for worker A on job 1 is $5 and on job 2 is $8. The cost for worker B on job 1 is $10 and on job 2 is $12. How should the work be divided using the assignment method?

A) worker A assigned to job 1 and worker B assigned to job 2
B) worker A assigned to job 2 and worker B assigned to job 1
C) worker A gets both jobs 1 and 2
D) worker B gets both jobs 1 and 2
E) unable to determine

Question 32

________ scheduling begins with the due date and schedules the final operation first and the other job steps in reverse order.

Question 33

A work center had planned outputs of 10, 15, 13, and 20 hours with actual outputs of 12, 14, 15, and 18 hours. What is the cumulative deviation in output?

A) 0
B) 1
C) −1
D) 58
E) Unable to determine with the given information

Question 34

The assignment method is:

A) a method to highlight overloads in a given work center.
B) a computerized method of determining appropriate tasks for an operation.
C) a form of linear programming for optimally assigning tasks or jobs to resources.
D) the same thing as the Gantt schedule chart.
E) a method for achieving a balance between forward and backward scheduling.

Question 35

If job 5 takes 3, 4, or 6 hours to be completed by workers A, B, and C, respectively, what would the row values for job 5 be after performing Step 1A of the assignment method?

A) 0, 1, 3
B) 8, 9, 11
C) 0, 1, 2
D) 6, 7, 9
E) 1, 4/3, 1/2

Question 36

Which of the following is NOT required to be known in order to schedule process-focused facilities?

A) the sequence of work
B) which workers are assigned to each work center
C) the time required for each item
D) the capacity of each work center
E) the availability of each work center

Question 37

A work center is interested in limiting work-in-process by not allowing production to start again until the current batch is finished. The best solution most likely involves:

A) MRP.
B) ConWIP cards.
C) Gantt charts.
D) Johnson's rule.
E) the assignment method.

Question 38

________ is the assignment of jobs to work or processing centers.

Question 39

What is a method of input-output control that uses a system of cards to limit the amount of work at a work center and also to control lead time and monitor backlog?

A) the assignment method
B) backward scheduling
C) forward scheduling
D) ConWIP cards
E) level material use

Question 40

Which of the following is an aid used to monitor jobs in progress?

A) a Gantt load chart
B) the assignment method
C) a Gantt schedule chart
D) Johnson's rule
E) a Gantt progress chart

Question 41

The ________ is a special class of linear programming models that involves assigning tasks or jobs to resources.

Question 42

If an assignment problem consists of 5 workers and 4 projects:

A) one worker will not get a project assignment.
B) one project will be assigned two workers.
C) the fifth worker will split time among the four projects.
D) one project will not get a worker assigned.
E) The problem cannot be solved by assignment method.

Question 43

What is the difference between a Gantt load chart and a Gantt scheduling chart?

Question 44

Three jobs are to be assigned to three machines. Cost for each job-machine combination appears in the table below. Perform the first two steps of the assignment method (subtract the smallest number in each row and subtract the smallest number in each column; then cover with straight lines). At this point in the problem-solving process:

A) the row for Job 1 contains the values 5, 6, and 0.
B) calculations are complete, and the problem is ready for an optimal set of assignments.
C) the column for Machine B indicates that it should be retired.
D) Job 1 should be performed on Machine B.
E) Job 1 should be performed on Machine A.

Question 45

Three jobs are to be assigned to three machines. Profits for each job-machine combination appear in the table below. Find the total profit using the assignment method.

A) 28
B) 40
C) 36
D) 39
E) 41

Question 46

What is the assignment method?

Question 47

________ cards are used to control the amount of work in a work center, aiding input-output control.

Question 48

Identify the major disadvantages of the Gantt load chart.

Question 49

The jobs listed below need to be completed. Assume that it is now day 140. If the jobs are sequenced according to the shortest processing time rule, what is the lateness of job A?

A) 0.0 days
B) 23.0 days
C) 7.4 days
D) 9.0 days
E) 11.6 days

Question 50

Lockport Marine Services, Inc. wishes to assign a set of jobs to a set of machines. The following table provides data on the cost of production of each job when performed on a specific machine.
(a) Determine the set of assignments that minimizes production cost.
(b) What is the total production cost of your assignments?

Question 51

________ are planning charts used to schedule resources and allocate time.

Question 52

Dispatching rules are typically judged by four effectiveness criteria: average completion time, utilization, average number of jobs in the system, and average customer satisfaction.

Question 53

The critical ratio sequencing rule prioritizes the jobs based on the importance or value of the customers who have placed the orders.

Question 54

Johnson's rule sequences a set of jobs through two different machines or work centers in the same order.

Question 55

If an assignment problem consists of 6 workers and 7 projects:

A) one worker will not get a project assignment.
B) one worker will be assigned two projects.
C) each worker will contribute work toward the seventh project.
D) one project will not get a worker assigned.
E) The problem cannot be solved by assignment method.

Question 56

Machines A, B, C, and D have been in use for several years, while machine E is new. The following table provides data on the value of production of each job when performed on a specific machine.
(a) Determine the set of assignments that maximizes production value.
(b) What is the total production value of your assignments?
(c) Which machine should be retired (i.e., gets no assignment)?

Question 57

Earliest due date is a shop floor dispatching (sequencing) rule that relates the time available to complete a job to the amount of work left to be completed.

Question 58

The president of a consulting firm wants to minimize the total number of hours it will take to complete four projects for a new client. Accordingly, she has estimated the time it should take for each of her top consultants-Charlie, Gerald, Johnny, and Rick-to complete any of the four projects, as follows:
(a) What is the total number of hours required by the following arbitrary assignment?
Charlie→B; Gerald→A; Johnny→C; Rick→D
(b) What is the optimal assignment of consultants to projects? (Use the assignment method.)
(c) For the optimal schedule, what is the total number of hours it will take these consultants to complete these projects?

Question 59

What is input-output control?

Question 60

Three jobs are to be assigned to three machines. Costs for each job-machine combination appear in the table below. Find the total cost using the assignment method.

A) 25
B) 28
C) 29
D) 21
E) 34

Question 61

Five jobs are waiting for processing through two work centers. Their processing time (in minutes) at each work center is contained in the table below. Each job requires work center Sigma before work center Delta. According to Johnson's rule, what sequence of jobs will minimize the completion time for all jobs?

A) R-S-T-U-V
B) V-S-U-T-R
C) S-U-T-V-R
D) V-R-U-S-T
E) R-T-V-S-U

Question 62

Five welding jobs are waiting to be processed. Their processing times and due dates are given below. Using the critical ratio dispatching rule, in which order should the jobs be processed? All dates are specified as days from today.

A) B, D, A, E, C
B) C, D, A, B, E
C) C, E, A, D, B
D) E, B, A, D, C
E) B, D, A, C, E

Question 63

EDD stands for what?

A) earliest due date
B) earliest design date
C) earliest detrimental date
D) earliest decision date
E) economic date determination

Question 64

Average completion time for a schedule sequence at a work center is the ratio of:

A) total processing time to the number of jobs.
B) total flow time to total processing time.
C) total flow time to the number of jobs.
D) total processing time plus total late time to the number of jobs.
E) total flow time plus total late time to the number of jobs.

Question 65

Eight jobs have been sequenced at a single work center. Total processing time for the eight jobs is 34 hours, and total flow time for the sequence is 85 hours. For this schedule, utilization is ________ and the average number of jobs in the system is ________.

A) 100 percent; 10.625
B) low; .0941
C) 0.400 or 40 percent; 2.5
D) 0.235 or 23.5 percent; 4.25
E) maximized; minimized

Question 66

What does the use of the shortest processing time sequencing rule generally produce?

A) maximum average lateness
B) maximum utilization
C) maximum effectiveness
D) minimum average flow time
E) B and D

Question 67

Sequencing (or dispatching):

A) assigns dates to specific jobs or operations steps.
B) assigns jobs to work centers.
C) specifies the order in which jobs should be done at each center.
D) assigns workers to jobs.
E) assigns workers to machines.

Question 68

Which of the following dispatching rules ordinarily gives the best results when the criterion is quickest time for completion of the full sequence of jobs?

A) shortest processing time (SPT)
B) critical ratio (CR)
C) first in, first out (FIFO)
D) first come, first served (FCFS)
E) longest processing time (LPT)

Question 69

Which of the following dispatching rules tends to minimize job flow time?

A) FCFS: first come, first served
B) SPT: shortest processing time
C) EDD: earliest due date
D) LPT: longest processing time
E) FCLS: first come, last served

Question 70

Five jobs are waiting to be processed. Their processing times and due dates are given below. Using the earliest due date dispatching rule, in which order should the jobs be processed?

A) C, E, A, D, B
B) A, B, C, D, E
C) B, D, A, E, C
D) C, B, A, E, D
E) B, D, A, C, E

Question 71

Orders are processed in the sequence in which they arrive if (the) ________ rule sequences the jobs.

A) earliest due date
B) slack time remaining
C) first come, first served
D) critical ratio
E) Johnson's

Question 72

When a set of jobs must pass through two workstations whose sequence is fixed, ________ is the sequencing rule most commonly applied.

A) critical ratio
B) earliest due date
C) first come, first served
D) slack time remaining
E) Johnson's rule

Question 73

Which critical ratio value implies that a job is already late?

A) more than 100
B) 1
C) less than 1
D) 10
E) 3.4

Question 74

What is the priority rule that sequences jobs using the smallest ratio of due date from today to processing time?

A) critical ratio
B) earliest due date
C) first come, first served
D) longest processing time
E) shortest processing time

Question 75

Five jobs are waiting for processing through two work centers. Their processing time (in minutes) at each work center is contained in the table below. Each job requires work center Alpha before work center Beta. According to Johnson's rule, which job should be scheduled first in the sequence?

A) R
B) S
C) T
D) U
E) V

Question 76

Using SPT priority would result in what sequence for Jobs A, B, C, and D if their process times are 4, 6, 5, and 2 respectively?

A) ABCD
B) DCBA
C) DACB
D) DABC
E) BCAD

Question 77

Which of the following is an advantage of the FCFS dispatching rule when used in services?

A) FCFS maximizes utilization.
B) FCFS minimizes the average number of jobs in the system.
C) FCFS minimizes the average lateness of all jobs.
D) FCFS maximizes the number of jobs completed on time.
E) FCFS seems fair to customers.

Question 78

The jobs listed below need to be completed. Assume that it is now day 140. If the jobs are sequenced according to the longest processing time rule, what is the average completion time?

A) 47.6 days
B) 65.2 days
C) 94.0 days
D) 2.5 days
E) 238.0 days

Question 79

Five jobs are waiting to be processed. Their processing times and due dates are given below. Using the shortest processing time dispatching rule, in which order should the jobs be processed?

A) D, B, E, A, C
B) C, A, E, B, D
C) B, D, A, E, C
D) D, A, E, B, C
E) C, E, A, B, D

Question 80

Flow time represents the time:

A) an order spends waiting for processing at a work center.
B) an order spends being processed at a work center.
C) an order spends moving from one work center to another.
D) to complete an order, including time spent in processing and in waiting.
E) none of the these